AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesTechnology, Industry, AgricultureHealth Care
PollenPollen TubePollinationRhinitis, Allergic, SeasonalLiliumBetulaAllergensFlowersAntigens, PlantAmbrosiaCupressusCryptomeriaPlant ProteinsGerminationOvulePlant InfertilitySelf-Incompatibility in Flowering PlantsAlnusOleaSeedsMeteorological ConceptsArabidopsisPoaceaeCedrusReproductionPapaverAngiospermsBeesTreesGametogenesis, PlantGene Expression Regulation, PlantImmunoglobulin EBetulaceaeArabidopsis ProteinsCupressaceaePlants, Genetically ModifiedPhleumSelf-FertilizationGerm Cells, PlantHypersensitivityGenes, PlantZea maysSkin TestsJuniperusDesensitization, ImmunologicSeasonsHoneyWindPetuniaFraxinusBrassicaArtemisiaLoliumTobaccoGametogenesis
Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.Pollen Tube: A growth from a pollen grain down into the flower style which allows two sperm to pass, one to the ovum within the ovule, and the other to the central cell of the ovule to produce endosperm of SEEDS.Pollination: The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).Rhinitis, Allergic, Seasonal: Allergic rhinitis that occurs at the same time every year. It is characterized by acute CONJUNCTIVITIS with lacrimation and ITCHING, and regarded as an allergic condition triggered by specific ALLERGENS.Lilium: A plant genus in the family LILIACEAE generally growing in temperate areas. The word lily is also used in the common names of many plants of other genera that resemble true lilies. True lilies are erect perennial plants with leafy stems, scaly bulbs, usually narrow leaves, and solitary or clustered flowers.Betula: A plant genus of the family BETULACEAE. The tree has smooth, resinous, varicolored or white bark, marked by horizontal pores (lenticels), which usually peels horizontally in thin sheets.Allergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Flowers: The reproductive organs of plants.Antigens, Plant: Substances found in PLANTS that have antigenic activity.Ambrosia: A plant genus of the family ASTERACEAE. The POLLEN is one cause of HAYFEVER.Cupressus: A plant genus of the family CUPRESSACEAE. Cypress ordinarily refers to this but also forms part of the name of plants in other genera.Cryptomeria: A plant genus of the family TAXODIACEAE. Its POLLEN is one of the major ALLERGENS.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Germination: The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)Ovule: The element in plants that contains the female GAMETOPHYTES.Plant Infertility: The failure of PLANTS to complete fertilization and obtain seed (SEEDS) as a result of defective POLLEN or ovules, or other aberrations. (Dict. of Plant Genet. and Mol. Biol., 1998)Self-Incompatibility in Flowering Plants: One of many different processes which occur in ANGIOSPERMS by which genetic diversity is maintained while INBREEDING is prevented.Alnus: A plant genus of the family BETULACEAE that is distinguished from birch (BETULA) by its usually stalked winter buds and by cones that remain on the branches after the small, winged nutlets are released.Olea: A plant genus of the family Oleaceae. The olive fruit is the source of olive oil.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Meteorological Concepts: The atmospheric properties, characteristics and other atmospheric phenomena especially pertaining to WEATHER or CLIMATE.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Poaceae: A large family of narrow-leaved herbaceous grasses of the order Cyperales, subclass Commelinidae, class Liliopsida (monocotyledons). Food grains (EDIBLE GRAIN) come from members of this family. RHINITIS, ALLERGIC, SEASONAL can be induced by POLLEN of many of the grasses.Cedrus: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. It is the source of cedarwood oil. Cedar ordinarily refers to this but also forms part of the name of plants in other genera.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Papaver: A genus of Eurasian herbaceous plants, the poppies (family PAPAVERACEAE of the dicotyledon class Magnoliopsida), that yield OPIUM from the latex of the unripe seed pods.Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Bees: Insect members of the superfamily Apoidea, found almost everywhere, particularly on flowers. About 3500 species occur in North America. They differ from most WASPS in that their young are fed honey and pollen rather than animal food.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Gametogenesis, Plant: The process of germ cell development in plants, from the primordial PLANT GERM CELLS to the mature haploid PLANT GAMETES.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Betulaceae: A plant family of the order Fagales, subclass Hamamelidae, class Magnoliopsida. They have simple, serrate, alternate leaves. Male flowers are borne in long, pendulous catkins; the female in shorter, pendulous or erect catkins. The fruit is usually a small nut or a short-winged samara.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Cupressaceae: A plant family of the order Pinales, class Pinopsida, division Coniferophyta (conifers). They are mainly resinous, aromatic evergreen trees.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Phleum: A plant genus of the family POACEAE that contains the Phl p 4 allergen.Self-Fertilization: The fusion of a male gamete with a female gamete from the same individual animal or plant.Germ Cells, Plant: The reproductive cells of plants.Hypersensitivity: Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.Genes, Plant: The functional hereditary units of PLANTS.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Skin Tests: Epicutaneous or intradermal application of a sensitizer for demonstration of either delayed or immediate hypersensitivity. Used in diagnosis of hypersensitivity or as a test for cellular immunity.Juniperus: A plant genus of the family CUPRESSACEAE. The species are slow growing coniferous evergreen trees or shrubs.Desensitization, Immunologic: Immunosuppression by the administration of increasing doses of antigen. Though the exact mechanism is not clear, the therapy results in an increase in serum levels of allergen-specific IMMUNOGLOBULIN G, suppression of specific IgE, and an increase in suppressor T-cell activity.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Honey: A sweet viscous liquid food, produced in the honey sacs of various bees from nectar collected from flowers. The nectar is ripened into honey by inversion of its sucrose sugar into fructose and glucose. It is somewhat acidic and has mild antiseptic properties, being sometimes used in the treatment of burns and lacerations.Wind: The motion of air relative to the earth's surface.Petunia: A plant genus of the family SOLANACEAE. Members contain steroidal glycosides.Fraxinus: A plant genus of the family OLEACEAE. Members contain secoiridoid glucosides.Brassica: A plant genus of the family Cruciferae. It contains many species and cultivars used as food including cabbage, cauliflower, broccoli, Brussel sprouts, kale, collard greens, MUSTARD PLANT; (B. alba, B. junica, and B. nigra), turnips (BRASSICA NAPUS) and rapeseed (BRASSICA RAPA).Artemisia: A plant genus of the family ASTERACEAE with strong-smelling foliage. It is a source of SANTONIN and other cytotoxic TERPENES.Lolium: Common member of the Gramineae family used as cattle FODDER. It harbors several fungi and other parasites toxic to livestock and people and produces allergenic compounds, especially in its pollen. The most commonly seen varieties are L. perenne, L. multiflorum, and L. rigidum.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Gametogenesis: The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).

Rational analyses of organelle trajectories in tobacco pollen tubes reveal characteristics of the actomyosin cytoskeleton. (1/2581)

To gain insight into the characteristics of organelle movement and the underlying actomyosin motility system in tobacco pollen tubes, we collected data points representing sequential organelle positions in control and cytochalasin-treated cells, and in a sample of extruded cytoplasm. These data were utilized to reconstruct approximately 900 tracks, representing individual organelle movements, and to produce a quantitative analysis of the movement properties, supported by statistical tests. Each reconstructed track appeared to be unique and to show irregularities in velocity and direction of movement. The regularity quotient was near 2 at the tip and above 3 elsewhere in the cell, indicating that movement is more vectorial in the tube area. Similarly, the progressiveness ratio showed that there were relatively more straight trajectories in the tube region than at the tip. Consistent with these data, arithmetical dissection revealed a high degree of randomlike movement in the apex, lanes with tip-directed movement along the flanks, and grain-directed movement in the center of the tube. Intercalated lanes with bidirectional movement had lower organelle velocity, suggesting that steric hindrance plays a role. The results from the movement analysis indicate that the axial arrangement of the actin filaments and performance of the actomyosin system increases from tip to base, and that the opposite polarity of the actin filaments in the peripheral (+-ends of acting filaments toward the tip) versus the central cytoplasm (+-ends of actin filaments toward to the grain) is installed within a few minutes in these tip-growing cells.  (+info)

Male gametic cell-specific gene expression in flowering plants. (2/2581)

The role of the male gamete-the sperm cell-in the process of fertilization is to recognize, adhere to, and fuse with the female gamete. These highly specialized functions are expected to be controlled by activation of a unique set of genes. However, male gametic cells traditionally have been regarded as transcriptionally quiescent because of highly condensed chromatin and a very reduced amount of cytoplasm. Here, we provide evidence for male gamete-specific gene expression in flowering plants. We identified and characterized a gene, LGC1, which was shown to be expressed exclusively in the male gametic cells. The gene product of LGC1 was localized at the surface of male gametic cells, suggesting a possible role in sperm-egg interactions. These findings represent an important step toward defining the molecular mechanisms of male gamete development and the cellular processes involved in fertilization of flowering plants.  (+info)

Exhaled and nasal NO levels in allergic rhinitis: relation to sensitization, pollen season and bronchial hyperresponsiveness. (3/2581)

Exhaled nitric oxide is a potential marker of lower airway inflammation. Allergic rhinitis is associated with asthma and bronchial hyperresponsiveness. To determine whether or not nasal and exhaled NO concentrations are increased in allergic rhinitis and to assess the relation between hyperresponsiveness and exhaled NO, 46 rhinitic and 12 control subjects, all nonasthmatic nonsmokers without upper respiratory tract infection, were randomly selected from a large-scale epidemiological survey in Central Norway. All were investigated with flow-volume spirometry, methacholine provocation test, allergy testing and measurement of nasal and exhaled NO concentration in the nonpollen season. Eighteen rhinitic subjects completed an identical follow-up investigation during the following pollen season. Exhaled NO was significantly elevated in allergic rhinitis in the nonpollen season, especially in perennially sensitized subjects, as compared with controls (p=0.01), and increased further in the pollen season (p=0.04), mainly due to a two-fold increase in those with seasonal sensitization. Nasal NO was not significantly different from controls in the nonpollen season and did not increase significantly in the pollen season. Exhaled NO was increased in hyperresponsive subjects, and decreased significantly after methacholine-induced bronchoconstriction, suggesting that NO production occurs in the peripheral airways. In allergic rhinitis, an increase in exhaled nitric oxide on allergen exposure, particularly in hyperresponsive subjects, may be suggestive of airway inflammation and an increased risk for developing asthma.  (+info)

LeProT1, a transporter for proline, glycine betaine, and gamma-amino butyric acid in tomato pollen. (4/2581)

During maturation, pollen undergoes a period of dehydration accompanied by the accumulation of compatible solutes. Solute import across the pollen plasma membrane, which occurs via proteinaceous transporters, is required to support pollen development and also for subsequent germination and pollen tube growth. Analysis of the free amino acid composition of various tissues in tomato revealed that the proline content in flowers was 60 times higher than in any other organ analyzed. Within the floral organs, proline was confined predominantly to pollen, where it represented >70% of total free amino acids. Uptake experiments demonstrated that mature as well as germinated pollen rapidly take up proline. To identify proline transporters in tomato pollen, we isolated genes homologous to Arabidopsis proline transporters. LeProT1 was specifically expressed both in mature and germinating pollen, as demonstrated by RNA in situ hybridization. Expression in a yeast mutant demonstrated that LeProT1 transports proline and gamma-amino butyric acid with low affinity and glycine betaine with high affinity. Direct uptake and competition studies demonstrate that LeProT1 constitutes a general transporter for compatible solutes.  (+info)

Process and current status of the epidemiologic studies on cedar pollinosis in Japan. (5/2581)

This paper reviews the present situation and future aspects of epidemiologic studies on Japanese cedar pollinosis. Increase of allergic rhinitis patients is observed in both the Patient Survey and the Reports on the Surveys of Social Medical Care Insurance Services, however, these surveys are conducted when cedar pollens do not pollute the air. Many have reported on the prevalence of pollinosis in limited areas but only a few nationwide epidemiologic surveys have been conducted. Most of the studies were conducted at special medical facilities such as university hospitals. There is a high possibility that patients who visit the specific facilities do not exactly represent the actual number of patients and epidemiologic pictures of pollinosis in Japan. The rapid advances in laboratory test methods may change the diagnostic criteria and increase the number of reported patients. Therefore, the prevalence of Japanese cedar pollinosis in Japan has not been determined yet. Determination of the prevalence of cedar pollinosis and description of the epidemiologic pictures constitute the essential steps toward the control of this clinical entity. Thus it is necessary to conduct an epidemiologic survey on Japanese representative samples with a standardized survey form with clear and concise diagnostic criteria.  (+info)

Pollen ultrastructure in anther cultures of Datura innoxia. I. Division of the presumptive vegetative cell. (6/2581)

Ultrastructural features of embryogenic pollen in Datura innoxia are described, just prior to, during, and after completion of the first division of the presumptive vegetative cell. In anther cultures initiated towards the end of the microspore phase and incubated at 28 degrees C in darkness, the spores divide within 24 h and show features consistent with those of dividing spores in vivo. Cytokinesis is also normal in most of the spores and the gametophytic cell-plate curves round the presumptive generative nucleus in the usual highly ordered way. Further differentiation of the 2 gametophytic cells does not take place and the pollen either switches to embryogenesis or degenerates. After 48-72 h, the remaining viable pollen shows the vegetative cell in division. The cell, which has a large vacuole and thin layer of parietal cytoplasm carried over from the microspore, divides consistently in a plane parallel to the microspore division. The dividing wall follows a less-ordered course than the gametophytic wall and usually traverses the vacuole, small portions of which are incorporated into the daughter cell adjacent to the generative cell. The only structural changes in the vegetative cell associated with the change in programme appear to be an increase in electron density of both plastids and mitochondria and deposition of an electron-dense material (possibly lipid) on the tonoplast. The generative cell is attached to the intine when the vegetative cell divides. Ribosomal density increases in the generative cell and exceeds that in the vegetative cell. A thin electron-dense layer also appears in the generative-cell wall. It is concluded that embryogenesis commences as soon as the 2 gametophytic cells are laid down. Gene activity associated with postmitotic synthesis of RNA and protein in the vegetative cell is switched off. The data are discussed in relation to the first division of the embryogenic vegetative cells in Nicotiana tabacum.  (+info)

Pollen ultrastructure in anther cultures of Datura innoxia. II. The generative-cell wall. (7/2581)

In young pollen grains of Datura innoxia, a wall of the usual hemispherical type separates the 2 gametophytic cells initially and, in the electron microscope, appears as an electron-translucent matrix which is contiguous with the intine. Before detachment of the generative cell from the intine, the matrix decreases in thickness and in places is dispersed altogether leaving the plasmalemmae on either side of it in close apposition. A particularly prominent zone, triangular in profile, is left where the wall joins with the intine. After detachment of the cell, remnants of the matrix can be seen distributed irregularly around the cell and it is supposed that these are partly derived from material in the triangular zone as the cell is drawn away from the intine. The wall residues persist throughout the maturation phase of the pollen and are considered to be either callose resulting from incomplete digestion of the initial wall, or some other polysaccharide material which is unevenly laid down along the wall and concentrated at the junction with the intine. In pollen induced into embryogenesis by anther culture, wall material is also distributed irregularly around the detached cell in a series of discrete zones, but these are more extensive than in vivo, closer together and in many instances highly dilated. The wall profiles thus have a beaded appearance, the 'beads' being connected together by short links of the 2 apposed plasmalemmae. The contents of the swollen zones have a similar electron density to that of the matrix in vivo but also show traces of a fibrillar component. It is postulated that this unusual swelling is a prelude to dispersal of the wall by disruption of the plasmalemmal links and to the establishment of cytoplasmic continuity between the 2 cells. The significance of such binucleate pollen grains in the formation of non-haploid embryos is discussed.  (+info)

Pollen ultrastructure in anther cultures of Datura innoxia. III. Incomplete microspore division. (8/2581)

During the microspore division in Datura innoxia, the mitotic spindle is oriented in planes both perpendicular (PE) and oblique (OB) to the spore wall against which the nucleus is situated. However, irrespective of polarity, the usual type of hemispherical wall is laid down at cytokinesis and isolates the generative cell from the rest of the pollen grain (type A). In PE spores the vegetative nucleus initially occupies a central position in the pollen grain, whereas in OB spores the vegetative nucleus lies at the periphery of the grain close to the generative cell. In anther cultures initiated just before the microspore division is due to take place, no marked change can be observed in either orientation or symmetry of the mitotic spindle when the spores divide. In some, however, cytokinesis is disrupted and deposition of the hemispherical wall arrested. In the absence of a complete wall, differentiation of the generative cell cannot take place and binucleate pollen grains are formed having 2 vegetative-type nuclei (type B). The 2 nuclei in the B pollens are always situated against the pollen-grain wall, suggesting that the disruption phenomenon is related to the OB spores. The incomplete wall always makes contact with the intine on the intine-side of the spindle. Wall material may be represented merely as short stubs projecting out from the intine into the cytoplasm, in which event the 2 nuclei lie close to each other and are separated by only a narrow zone of cytoplasm. In other grains the wall is partially developed between the nuclei and terminates at varying distances from the tonoplast; in these, the nuclei are separated by a wider zone of cytoplasm. The significance of these binucleate grains in pollen embryogenesis is discussed.  (+info)

sidecar pollen, an Arabidopsis thaliana male gametophytic mutant with aberrant cell divisions during pollen development |...sidecar pollen, an Arabidopsis thaliana male gametophytic mutant with aberrant cell divisions during pollen development |...
During pollen development each product of meiosis undergoes a stereotypical pattern of cell divisions to give rise to a three-celled gametophyte, the pollen grain. First an asymmetric mitosis generates a larger vegetative cell and a smaller generative cell, then the generative cell undergoes a second mitosis to give rise to two sperm cells. It is unknown how this pattern of cell divisions is controlled. We have identified an Arabidopsis gene, SIDECAR POLLEN, which is required for the normal cell division pattern during pollen development. In the genetic background of the NoO ecotype, sidecar pollen heterozygotes have about 45% wild-type pollen, 48% aborted pollen and 7% pollen with an extra cell. Homozygous sidecar pollen plants have about 20% wild-type pollen, 53% aborted pollen and 27% extra-celled pollen. Similar ratios of sidecar pollen phenotypes are seen in the Columbia ecotype but sidecar pollen is a gametophytic lethal in the Landsberg erecta ecotype. Thus this allele of sidecar pollen ...
Technique for In Vitro Pollen Germination and Short-term Pollen Storage in Caladium in: HortScience Volume 39 Issue 2 (2004)Technique for In Vitro Pollen Germination and Short-term Pollen Storage in Caladium in: HortScience Volume 39 Issue 2 (2004)
The sporadic nature of inflorescence production and flower protogyny in caladium (Caladium ×hortulanum Birdsey) makes it desirable to store pollen and to rapidly assess its viability for cross-pollinations in breeding programs. This study was conducted to develop a procedure to determine caladium pollen viability and to use that procedure to evaluate the effect of short-term storage conditions on pollen viability. The sucrose level in the culture medium was found to have a significant impact on the in vitro germination of caladium pollen; a concentration of 6.8% was determined to be optimal for pollen germination. Caladium pollen lost viability within 1 day under room (24 °C) or freezing (-20 °C) temperatures, but could be stored at 4 °C for 2 to 4 days. Pollen stored at 4 °C produced successful pollinations. Data obtained from large-scale greenhouse pollinations supported use of this in vitro germination assay as a convenient way to evaluate caladium pollen viability (and fertility). ...
Grass pollen surface ornamentation: a review of morphotypes and taxonomic utility | Journal of Micropalaeontology |...Grass pollen surface ornamentation: a review of morphotypes and taxonomic utility | Journal of Micropalaeontology |...
The classification of grass pollen is a classic problem in palynology. One approach to this problem is to image grass pollen using scanning electron microscopy (SEM) and to construct morphotypes on the basis of surface ornamentation patterns. In this paper, we construct a database of published SEM images of grass pollen surface ornamentation and use this database to review the status and utility of grass pollen morphotypes. Very little SEM data on grass pollen surface ornamentation have been collected. There are more SEM data on the pollen of species from larger subfamilies such as the Pooideae, but there are no SEM data on the pollen of relatively small subfamilies or the early-diverging APP clade of grasses. The available data support the following six morphotypes: the Hordeum-type, Triticum-type, Avena-type, Setaria-type, Pariana-type and Stipa-type. The phylogenetic distribution of these morphotypes cannot be assessed reliably with the available data, but the Pariana and Stipa types are ...
Timothy grass pollen allergen extract Uses, Side Effects & Warnings - Drugs.comTimothy grass pollen allergen extract Uses, Side Effects & Warnings - Drugs.com
Physician reviewed timothy grass pollen allergen extract patient information - includes timothy grass pollen allergen extract description, dosage and directions.
World Allergy Organization Study on Aerobiology for Creating First Pollen and Mold Calendar With Clinical Significance in...World Allergy Organization Study on Aerobiology for Creating First Pollen and Mold Calendar With Clinical Significance in...
Three years data of aerobiology of Islamabad (2005, 2006, and 2007) indicate that Islamabad is among the cities with highest pollen counts in the world. In our study of 3 years, highest pollen count was that of B. papyrifera on 10th March 2006 (34, 320 pollens/m3 air). The highest pollen count was seen in study of Domínguez[15] with data of last 25 years indicating that in Andalusia, South Spain, the higher pollen count belonged to Olea europaea. During only one day (May 22, 1991), 38, 393 olive pollen grains per cubic meter were detected in the air in Córdoba city [15].. For the first time, pollen and mold calendar of Islamabad was prepared from 3-year study (Tables 5, 4, 5). In spring (March to April), B. papyrifera pollens are the causes of severe allergic diseases like asthma, allergic rhinitis, and urticaria, whereas in fall (July to September), pollens of Cannabis are causing these allergic diseases. Grass pollens and molds are present throughout the year and are causing the above ...
PollenPollen
... is a fine powder consisted of microspores (pollen grains), which are the male gametes of higher plants. Pollen is produced in the microsporangium (antherss of an angiosperm flower). Pollen grains come in a wide variety of shapes, sizes, and surface markings characteristic of the species (see photomicrograph at right). Most, but certainly not all, are spherical. Pollen grains of pines, firs, and spruces are winged. The smallest pollen grain, that of the Forget-me-not plant (Myosotis sp.), is around 6 μm (0.006 mm) in diameter. The study of pollen is called Palynology and is highly useful in paleontology, archeology, and forensics.. The transfer of pollen grains to the female reproductive structure (carpel in angiosperms) is called pollination. Allergy to pollen is called hay fever. Generally pollens that cause allergies are those of anemophilous (literally wind-loving) plants, which produce very lightweight pollen grains in great quantities for wind dispersal, and subsequently contacting ...
CPIB » Biomechanical modelling of anther dehiscence and pollen releaseCPIB » Biomechanical modelling of anther dehiscence and pollen release
Understanding the processes which underlie pollen release is key to efficient production of hybrid crops. Pollen is produced in compartments termed locules, which reside within the anther. Surrounding the locules are two cell layers: an outer epidermis and an inner endothecium. During pollen development, endothecial cells undergo secondary thickening - a process by which cell walls are lined by a helical arrangement of lignin fibres, strengthening the layer and providing a natural resistance to bending. Pollen release occurs as a result of an anther dehiscence process, during which the anther wall splits, exposing the pollen to the environment. A number of processes have been proposed to drive this process. In this report, we examine one such process: that in which anther dehiscence is driven by dehydration of the epidermis, which results in contraction of this layer and an associated change to the preferred curvature of the locule. We extend an existing bilayer model to incorporate expansion ...
Pollen is... - University of LeicesterPollen is... - University of Leicester
Pollen is the haploid microgametophyte generation in seed plants and is considered the male partner in sexual reproduction. In flowering plants pollen comprises either two or three cells when shed from the flower. Both pollen types possess a large vegetative cell containing within, a single generative cell (bicellular pollen) or sperm cell pair (tricellular pollen). Pollen shows a wide variation in size, shape and surface patterning. Pollen grains vary in diameter from 5 µm in Myosotis (forget-me-not) to more than 200 µm in Curcurbita (ie melon) and round, ellipsoid and multifaceted pollen types occur ...
Evaluation of pollen viability and fertility of triploid herbaceous peony cultivars | International Society for Horticultural...Evaluation of pollen viability and fertility of triploid herbaceous peony cultivars | International Society for Horticultural...
To fully understand the breeding potential of triploid herbaceous peony cultivars, and to promote the development of new peony cultivars and extend their culture in China, three triploid cultivars, Brightness, Roselette and Coral Sunset, were selected to investigate their pollen viability and fertility. In addition, fluorescence microscopy was used to observe pollen germination and pollen tube growth on the stigma of the domestic diploid cultivar Fen Yu Nu, which was used as the female parent of the three triploid cultivars. Our results show that pollen viability of the three triploid cultivars was very low, being highest (6.7%) in Brightness and lowest (2.2%) in Coral Sunset, and that the pollen grains of the three triploid cultivars had a very low germination rate on the maternal stigma, caused by very short pollen tubes that could not penetrate the stigma. Profuse callose was found in papillose cells of the stigma and pollen tubes and a large number of pollen grains detached from ...
Pollen Monitoring | BathnesPollen Monitoring | Bathnes
Hay Fever sufferers can gain a great advantage in the management of their symptoms if they are made aware of the daily pollen count. This can enable them to plan ahead in their use of drugs and in their exposure to possible pollen sources.. The Councils Environmental Monitoring Team provides daily counts of the grass pollen levels measured in the Bath area. The grass pollen monitoring usually takes place from May or June to August.. This monitoring is carried out on behalf of the Met Office and the National Pollen and Aerobiology Research Unit (NPARU) and is part of a UK network of pollen monitoring sites.. Pollen is collected via a pollen trap located in as open an area as possible then analysed under the microscope to give the final count. More Information on the Pollen Forecast can be found on the Met Office Web site: http://www.metoffice.gov.uk/health/public/pollen-forecast. ...
POLLEN | The Handbook of Texas Online| Texas State Historical Association (TSHA)POLLEN | The Handbook of Texas Online| Texas State Historical Association (TSHA)
POLLEN. Though palynology, which denotes the study of pollen and spores, is not a household word in Texas, the allergic effects of airborne pollen and spores are well known throughout the state. In technical terms, pollen is the microscopic mature or immature multinucleate gametophyte generation of seed plants. Its most important function is to carry the sperms needed for plant reproduction. A spore, on the other hand, is a cellular agent of asexual reproduction. Spores and pollen are similar in shape and size, in their ability to remain preserved in sediments for millions of years, and in their ability to be produced and dispersed by the millions. In addition, each spore or pollen grain type is morphologically unique to its plant species.. Each year thousands of Texans are immobilized by the crippling effects and allergic reactions caused by inhaling pollen and spores. It is estimated that the pollen count exceeds 500 pollen grains and spores per cubic meter of air during an average spring day ...
Brassinosteroids and gibberellic acid: effects on in vitro pollen germination in grapevine | OENO OneBrassinosteroids and gibberellic acid: effects on in vitro pollen germination in grapevine | OENO One
In this study, the response of pollens obtained from inflorescences of table grape cultivars Italia and Cardinal to different plant growth regulators added to the medium in Petri dishes was evaluated. Statistical analysis showed that pollen germination of cv. Italia was not influenced (p≥0.05) by the plant growth regulators (Table 1). Pollens not treated with any plant growth regulators (control) showed 26.08% germination, while the highest ratio was obtained from 0.001 mg L-1 EBR treatment (44.40%). The lowest percentage of germination was obtained from the application of 0.1 mg L-1 HBR (17.85%). Although no significant differences were observed, it was seen in the mean values of the applications that as the amount of GA3 in the combination treatments increased, the mean ratio of pollen germination slightly decreased. In addition, homobrassinolide yielded higher germination compared to epibrassinolide. Pollens of cv. Cardinal, on the other hand, responded significantly (p≤0.01) ...
Atmospheric Phenomena: Cedar Pollen CoronaAtmospheric Phenomena: Cedar Pollen Corona
Cypress pollen is another source of pollen coronae in Japan. However, the season of Japanese cypress pollen is almost same as that of our cedar pollen so that it is hard to distinguish its contribution from the cedar pollens contribution. (The amount of cypress pollen is less than cedar pollen ...
Maize pollen deposition in relation to distance from the nearest pollen source under common cultivation - results of 10 years...Maize pollen deposition in relation to distance from the nearest pollen source under common cultivation - results of 10 years...
Wind pollination is a successful strategy for many plants, and pollen can be transported over long distances. Many agricultural or biological questions relate to gene flow mediated by pollen, and information on gene flow is crucial to understand introgression and seed purity. However, it is important to distinguish between work carried out on gene flow (including cross pollination) and that carried out on pollen deposition itself. This is also true for assessing genetically modified (GM) crops. With GM crops, gene flow may lead either to introgression into wild relatives [1]-[3] or to the presence of GM material in seeds, harvested materials, feed, or foodstuffs. Because there is a legal obligation for GM and GM-free agriculture to co-exist in Europe [4],[5], much research has been carried out to understand and manage gene flow from GM crops to other crops of the same or closely related species [6]-[13].. Pollen dispersal, independent of its ability to facilitate vertical gene flow, has been ...
pollen health effectspollen health effects
These symptoms could be contributed to a pollen allergy, typically referred to as hay fever.. Weeds, grasses, trees, and some shrubs are the common culprits for pollen. Weeds have commonly been determined to be the most productive of pollen producers and are identified as the plant that causes the most allergies.. How does pollen cause my symptoms?. When pollen is inhaled through the nose and throat, the body experiences an immune response that results in hay fever, because it attaches to the cells and creates histamine. It is this releasing of histamine that causes the symptoms of pollen allergy.. How can I avoid pollen?. The most overlooked way to avoid pollen is a simple change of your home air filter. Air filters are proven to reduce many of the common airborne contaminants, such as pollen, from the air you breathe. In addition to changing your air filter on a regular basis, here are some other things you can do to avoid pollen this spring:. ...
Transformation of hard pollen into soft matter | Nature CommunicationsTransformation of hard pollen into soft matter | Nature Communications
Pollens practically-indestructible shell structure has long inspired the biomimetic design of organic materials. However, there is limited understanding of how the mechanical, chemical, and adhesion properties of pollen are biologically controlled and whether strategies can be devised to manipulate pollen beyond natural performance limits. Here, we report a facile approach to transform pollen grains into soft microgel by remodeling pollen shells. Marked alterations to the pollen substructures led to environmental stimuli responsiveness, which reveal how the interplay of substructure-specific material properties dictates microgel swelling behavior. Our investigation of pollen grains from across the plant kingdom further showed that microgel formation occurs with tested pollen species from eudicot plants. Collectively, our experimental and computational results offer fundamental insights into how tuning pollen structure can cause dramatic alterations to material properties, and inspire future
HKU Scholars Hub: F-Actin visualization in generative and sperm cells of living pollen of rice using a GFP-Mouse talin fusion...HKU Scholars Hub: F-Actin visualization in generative and sperm cells of living pollen of rice using a GFP-Mouse talin fusion...
Green fluorescent protein (GFP) fused to the F-acton binding domain of mouse talin labels the actin cytoskeleton in the living generative and sperm cells of a third generation transgenic rice (Oryza sativa L.) plant, A005-G-T 1-2. Observations were made on pollen at four major developmental stages, viz. I. uni-nucleate microspore stage; II. early bi-cellular pollen stage; III. late bi-cellular pollen stage; and IV. tri-cellular pollen stage. At each of these developmental stages vegetative nucleus, generative nucleus/ cell, and sperm cells were seen undergoing continuous and coordinated motion and migration. These movements seemed to be influenced by associated microfilament networks existing in the pollen. Based on these observations we propose that it is the interaction between the microfilament networks (usually one existing in the central cytoplasm and another in the cortex) that controls the dynamic movement of the vegetative nucleus, generative nucleus/cell and sperm cells. Furthermore, we ...
Pollen Performance Traits Reveal Prezygotic Nonrandom Mating and Inter by Robert Swanson, Adam T. Hammond et al."Pollen Performance Traits Reveal Prezygotic Nonrandom Mating and Inter" by Robert Swanson, Adam T. Hammond et al.
PREMISE: The lack of ability to measure pollen performance traits in mixed pollinations has been a major hurdle in understanding the mechanisms of differential success of compatible pollen donors. In previous work, we demonstrated that nonrandom mating between two accessions of Arabidopsis thaliana, Columbia (Col) and Landsberg (Ler), is mediated by the male genotype. Despite these genetic insights, it was unclear at what stage of reproduction these genes were acting. Here, we used an experimental strategy that allowed us to differentiate different pollen populations in mixed pollinations to ask: (1) What pollen performance traits differed between Col and Ler accessions that direct nonrandom mating? (2) Is there evidence of interference competition? METHODS: We used genetically marked pollen that can be visualized colorimetrically to quantify pollen performance of single populations of pollen in mixed pollinations. We used this and other assays to measure pollen viability, germination, tube growth,
PERSISTENT TAPETAL CELL1 Encodes a PHD-Finger Protein That Is Required for Tapetal Cell Death and Pollen Development in Rice |...PERSISTENT TAPETAL CELL1 Encodes a PHD-Finger Protein That Is Required for Tapetal Cell Death and Pollen Development in Rice |...
In higher plants, timely degradation of tapetal cells, the innermost sporophytic cells of the anther wall layer, is a prerequisite for the development of viable pollen grains. However, relatively little is known about the mechanism underlying programmed tapetal cell development and degradation. Here, we report a key regulator in monocot rice (Oryza sativa), PERSISTANT TAPETAL CELL1 (PTC1), which controls programmed tapetal development and functional pollen formation. The evolutionary significance of PTC1 was revealed by partial genetic complementation of the homologous mutation MALE STERILITY1 (MS1) in the dicot Arabidopsis (Arabidopsis thaliana). PTC1 encodes a PHD-finger (for plant homeodomain) protein, which is expressed specifically in tapetal cells and microspores during anther development in stages 8 and 9, when the wild-type tapetal cells initiate a typical apoptosis-like cell death. Even though ptc1 mutants show phenotypic similarity to ms1 in a lack of tapetal DNA fragmentation, delayed ...
Insects | Free Full-Text | A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves | HTMLInsects | Free Full-Text | A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves | HTML
Maize is wind pollinated and produces huge amounts of pollen. In consequence, the Cry toxins expressed in the pollen of Bt maize will be dispersed by wind in the surrounding vegetation leading to exposure of non-target organisms (NTO). NTO like lepidopteran larvae may be affected by the uptake of Bt-pollen deposited on their host plants. Although some information is available to estimate pollen deposition on host plants, recorded data are based on indirect measurements such as shaking or washing off pollen, or removing pollen with adhesive tapes. These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves. Here, we present a new method for recording in situ the amount and the distribution of Bt-maize pollen deposited on host plant leaves. The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software), which can be used in combination with a notebook in the
Bee pollen allergic reaction symptoms - Things You Didnt KnowBee pollen allergic reaction symptoms - Things You Didn't Know
Bee pollen allergic reaction symptoms - Are the health food store bee pollen meds just a gimmick for treating allergies? Yes. The pollens that cause allergies are very small, and carried by the wind. Flowers need bees to cross-pollinate, because the pollen is too big and heavy to be carried by the wind. Since theyre not airborne, people cant inhale them and react to them. Thus, the pollens found in bee pollen are not the pollens that cause your allergic symptoms.
Immunological Interactive Effects between Pollen Grains and Their Cytoplasmic Granules on Brown Norway Rats | World Allergy...Immunological Interactive Effects between Pollen Grains and Their Cytoplasmic Granules on Brown Norway Rats | World Allergy...
In this study, immunologic interactive effects between timothy grass pollen grains and their PCGs were performed by an evaluation of allergy (humoral and cellular responses) and inflammatory parameters on Brown Norway rats, a good animal model of pollen allergy [17]. In parallel, allergic and inflammatory responses of these interactive effects were compared with those obtained on rats sensitized and challenged with only one aeroallergen, pollen grains or PCGs.. Our findings showed that combined effects between pollen and PCGs induce humoral responses. Previous studies showed that PCGs and pollen grains induced humoral responses on Brown Norway rats [9, 10, 16] when each aeroallergenic source was used for both sensitization and challenge. PCGs can also trigger IgE-mediated reactions in grass pollen-sensitive patients [4].. Humoral responses on allergic PG and GP groups were influenced mainly by PCGs. On these groups (PG and GP groups), the IgE and IgG1 levels were not different from those ...
About Pollen in Global Pollen PattiesAbout Pollen in Global Pollen Patties
Pollen is the natural food of bees and provides most of the nutrients bees require for growth and health. Honey provides very little nutrition, except carbohydrates which are essential for heat and movement. Pollen supplies all the rest, and bees cannot live long or raise brood for long without pollen.. Ingredients like properly selected brewers yeast and soy flours (but not all kinds) can come quite close to the bees needs for amino acids (protein), but adding natural pollen improves the diet considerably particularly when bees are not able to forage for pollen and also increases the rate of patty consumption. If the bees can get some natural pollen outside the hive, then supplements alone can be sufficient.. We make patties with various percentages of pollen, as well as straight supplement, and although most people request pollen, yeast, soy & sugar, we can make patties with any ingredients you request, including BeePro , MegaBee , FeedBee or other ingredients like egg or casein. (See ...
PollenPollen
Nutritional Benefits of Pollen - Bee pollen is a nutrient rich food supplement easily added to your regular diet. There is a lot of myth and misinformation about the benefits of bee pollen. It contains 22 known essential nutritional elements which are beneficial to humans .. Bee pollen may be eaten by the teaspoonful as a food supplement. We recommend ½ a teaspoon twice daily. Stir it into yogurt, honey, or applesauce. Sprinkle it on your salad or cereal or take it straight with water or fruit juice. If you are a new pollen consumer, start off with small doses (4-6 pellets) to gauge how your bodys system will accept pollen. Doing so will help minimize a reaction to the natural substance. Like any food, there is a small chance of an allergic reaction to the pollen. Speak with your doctor if you have any concerns regarding bee pollen and allergies.. ...
Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment<...Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment<...
TY - JOUR. T1 - Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment. AU - Viner, Brian J.. AU - Arritt, Raymond W.. AU - Westgate, Mark E.. PY - 2017/8/1. Y1 - 2017/8/1. N2 - Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kauai during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to ...
Bee Pollen | StayWell Health Library | MainBee Pollen | StayWell Health Library | Main
Bee Pollen Other name(s): pollen General description Pollen is found in flowering plants. Bees collect pollen while theyre searching for nectar. Pollen can be gathered from bees. It can also be harvested from plants by machines. Bee pollen contains the male reproductive cells (gametes) of flowers. It also contains digestive enzymes from bees. Pollen is rich in vitamins, minerals, trace elements, enzymes, and amino acids. Its also an excellent source of antioxidants. Its exact composition varies. This ...
Influence of intranasal steroids during the grass pollen season on bronchial responsiveness in children and young adults with...Influence of intranasal steroids during the grass pollen season on bronchial responsiveness in children and young adults with...
We investigated whether the use of an intranasal corticosteroid can modify BHR during the grass pollen season in patients with mild asthma and seasonal allergic rhinitis. The effect of FP on BHR was studied in one season and the effect of equipotent doses of FP and BDP was studied in the next season. In the first season we found a significant and equal increase in BHR in patients in both the FP and placebo groups. In the next season we observed no increase in BHR in patients given placebo nor in those treated with BDP or FP. As expected, we found a decrease in nasal symptoms with intranasal corticosteroids. Rather unexpectedly, we found an improvement in % predicted FEV1 under low allergen exposure in the patients treated with BDP or FP. Thus, intranasal steroids were not able to prevent the increase in BHR which occurred in the first season nor to reduce BHR in the second season.. The increase in BHR during the grass pollen season is thought to be caused by a gradual cumulative effect of ...
All About Pollen Allergies - KTRE.com | Lufkin and Nacogdoches, TexasAll About Pollen Allergies - KTRE.com | Lufkin and Nacogdoches, Texas
Each spring, summer, and fall, tiny particles are released from trees, weeds, and grasses. These particles, known as pollen, hitch rides on currents of air. Although their mission is to fertilize parts of other plants, many never reach their targets. Instead, they enter human noses and throats, triggering a type of seasonal allergic rhinitis called pollen allergy, which many people know as hay fever or rose fever (depending on the season in which the symptoms occur). Of all the things that can cause an allergy, pollen is one of the most widespread. Many of the foods, drugs, or animals that cause allergies can be avoided to a great extent; even insects and household dust are escapable. Short of staying indoors when the pollen count is high--and even that may not help--there is no easy way to evade windborne pollen.. People with pollen allergies often develop sensitivities to other troublemakers that are present all year, such as dust mites. For these allergy sufferers, the "sneezin season" has ...
Ragweed pollen grains, SEM - Stock Image C002/6317 - Science Photo LibraryRagweed pollen grains, SEM - Stock Image C002/6317 - Science Photo Library
Ragweed (Ambrosia sp.) pollen grains (yellow) sticking to an anther, scanning electron micrograph (SEM). Pollen grains are reproductive structures produced by the male parts of flowering plants. Ragweed releases 1.6 million pollen grains per hour, which are highly allergic and a major contributor to hayfever. - Stock Image C002/6317
Effects of Dietary Propolis and Pollen on Growth Performance, Fecundity IntroductionEffects of Dietary Propolis and Pollen on Growth Performance, Fecundity Introduction
Turkish Journal of Fisheries and Aquatic Sciences 12: 851-859 (2012) www.trjfas.org ISSN 1303-2712 DOI: 10.4194/1303-2712-v12_4_13 Effects of Dietary Propolis and Pollen on Growth Performance, Fecundity and Some Hematological Parameters of Oreochromis niloticus Amany A. Abbass1,*, Amel M. El-Asely1, Mohamed M.M. Kandiel1 1 Benha University, Faculty of Veterinary Medicine, Deptartment of Fish Diseases and Management, Banha, Al Qalyubiyah, Egypt. * Corresponding Author: Tel.: +2013 2461 411; Fax: +2013 2461 411; E-mail: [email protected] Received 16 July 2012 Accepted 18 October 2012 Abstract This study aimed at identifying the effects of propolis and honeybee pollen (HBP) on growth performance, fecundity and some hematological indices of liver and kidney functions of Nile tilapia Oreochromis niloticus supplemented with 2.5% of propolis or HBP in diet for 21 days. The results showed that dietary propolis or HBP significantly (P,0.05) improved Specific Growth Rate (SGR), Average Daily Gain ...
bee pollen •bee pollen •
Researchers from Purdue University then monitored the pollen sources and pesticide levels over a period of 16 weeks. Krupke was surprised to find out that the bees had the tendency to wander off to different plants, even though the hives were set next to corn fields. In fact, crop pollen was a minor part of what the insects collected. This provided proof that bees are more exposed to chemicals than previously thought. Bee pollen is full of pesticides, scientists found. The different kinds of pesticides discovered in the pollen samples were overwhelming.. Kupke found 29 pesticides in the meadow sites pollen, 29 pesticides in the pollen from treated corn fields. A staggering number of 31 pesticides were found in the pollen from untreated corn fields.. Some pesticides were expected. For example, neonicotinoids. These were known to cause a decline in the population of bees, as previous studies already showed. Apart from neonicotinoids, researchers found high amounts of pyrethroids as well. This is ...
High Quality Bee Pollen Tablet, Bee Pollen Caspule & Bee Pollen - Honey Products - Agriculture & Food - Products - Cxhuayu.comHigh Quality Bee Pollen Tablet, Bee Pollen Caspule & Bee Pollen - Honey Products - Agriculture & Food - Products - Cxhuayu.com
Bee pollen1. Source: Multiflower, corn, rape, tea, etc.2. Specification:A. Bee pollen granuleB. Bee pollen powder 80-120meshC. Bee pollen tabletD....
The significance of pollen signal in present-day marine terrigenous sediments : The example of the Gulf of Lions (western...The significance of pollen signal in present-day marine terrigenous sediments : The example of the Gulf of Lions (western...
Tenigenous marine and continental sediments constitute pollen reservoirs able to fulfil the lack of Pleistocene data extracted from autochtonous lacustrine sediments for palaeovegetation reconstructions. Nevertheless, it is essential to constrain the signification of the pollen signal in such still under-exploited sediments. This article introduces a study carried out on the shelf of the Gulf of Lions. It aims at (1) highlighting the transport of pollen grains and the signification of the record in that area as well as at (2) discussing the pollen transport in various sedimentary contexts. The present study was carried out on surface water of the Rhone River, sea water and surface sediments of the shelf of the Gulf of Lions. The pollen content of the Rhone River and of its plume is in agreement with the season of sampling. On the contrary, the other samples of sea water did not contain any pollen grain. The samples from the surface sediments of the shelf are very rich in pollen grains and ...
Airborne pollen spectra at three sites in inland Croatia, 2003Airborne pollen spectra at three sites in inland Croatia, 2003
Pollen of anemophilous plants prevailed at all monitoring sites while pollen of entomophilous taxa occurred sporadically or in very low amounts. A similar pattern was reported in southeast Poland, however, with a different floral composition due to climatic differences. In Poland, pollen of the allergenic alder tree (Alnus sp.) accounts for most of the pollen count while in central Croatia the most allergenic weed, ragweed (Ambrosia sp.) does (Kasprzyk, 1999). Monthly pollen concentrations showed two peaks, in April and August, at all three sampling sites. These peaks coincided with the flowering of generally anemophilous tree and weed, especially ragweed. Similar results have also been reported from central Italy and south France (Clot, 2001; Emberlin et al., 1993; Spieksma and Frenguelli, 1991; J ger et al., 1991). Between-site differences were observed: monthly pollen concentrations measured in April at the Zagreb and Samobor sampling sites exceeded those recorded at the Ivani c Grad sampling ...
Daisy pollen (Helianthus sp.), SEM - Stock Image C032/4451 - Science Photo LibraryDaisy pollen (Helianthus sp.), SEM - Stock Image C032/4451 - Science Photo Library
Sunflower pollen (Helianthus sp), coloured scanning electron micrograph (SEM). The outer wall (exine) has many small spiky projections. The pollen gets caught in the body hairs of insects visiting the flower. Cross pollination occurs when insects fly to another similar flower and pollen is left behind. Pollen contains the male reproductive cells of a plant. When the pollen grain, containing the male gametes, lands on the stigma of a flower, it germinates. A pollen tube grows out from the germinal pore, down through the stigma, to the ovary. The male nuclei pass down the tube, fertilize the ovules and seed is formed. Humans can also be allergic to daisy pollen. Magnification: x260 when shortest axis printed at 25 millimetres. - Stock Image C032/4451
What are the Health Benefits of Bee Pollen? - Holistic Home FitnessWhat are the Health Benefits of Bee Pollen? - Holistic Home Fitness
I have been using a bee pollen supplements product for about two years now and I really do believe its been the main reason why Ive avoided colds and flu when the rest of my family have come down with them on a regular basis. I sometimes feel a cold coming on, but by the next morning symptoms disappeared. I dont suffer any allergic reactions or side effects to this amount of bee pollen. A lot of people take bee pollen, but what are the benefits of bee pollen, how much should you take and are there any health studies to back up the claims made by so many for "this miracle supplement"?. I personally take about 15 g of the pollen a day and find that to be effective, but the doses that other people recommend varying enormously. For example in Robert Risters book "Healing Without Medication", he suggests that bee pollen should not be taken for any more than two weeks of the time to prevent forming an allergy to the preparation. He also quotes typical doses as 1 - 1.5 grams per day which is well ...
Genetic stability in triticale estimated by pollen viabilityGenetic stability in triticale estimated by pollen viability
BRAMBATTI, Adriana; BRAMMER, Sandra Patussi; WIETHOLTER, Paula e NASCIMENTO JUNIOR, Alfredo do. Genetic stability in triticale estimated by pollen viability. Arq. Inst. Biol. [online]. 2016, vol.83, e0802014. Epub 15-Dez-2016. ISSN 0020-3653. https://doi.org/10.1590/1808-1657000802014.. The study aimed to infer about the genetic stability from the pollen viability in hexaploid triticale genotypes used in block crossings breeding program from Brazilian Company of Agriculture Research (Embrapa Wheat). The experiments were conducted in a randomized design. For each genotype five repetitions were assessed. Each replication consisted of one plant and each replication consisted of one plant. Two hundred pollen grains were analyzed by optical microscopy and by the squash technique with 1% acetic carmine dye per slide, totalizing 1,000 pollen grains per genotype. The variables analyzed were: binucleate and trinucleate pollen grains, with little starch, empty, with more than one pore and with different ...
Forever Bee Pollen - product | Forever KnowledgeForever Bee Pollen - product | Forever Knowledge
Bee pollen, dubbed a miracle food, is a nutritionally-rich substance that provides bees with everything they need to survive. Forever sources its pollen using a patented pollen trap which collects pollen without destroying the colony. This pollen has then been combined with honey and royal jelly to create Forever Bee Pollen, a fresh and potent supplement.
Leicester Research Archive: A conserved, Mg²+-dependent exonuclease degrades organelle DNA during Arabidopsis pollen...Leicester Research Archive: A conserved, Mg²+-dependent exonuclease degrades organelle DNA during Arabidopsis pollen...
In plant cells, mitochondria and plastids contain their own genomes derived from the ancestral bacteria endosymbiont. Despite their limited genetic capacity, these multicopy organelle genomes account for a substantial fraction of total cellular DNA, raising the question of whether organelle DNA quantity is controlled spatially or temporally. In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. By staining mature pollen grains with fluorescent DNA dye, we screened Arabidopsis thaliana for mutants in which extrachromosomal DNAs had accumulated. Such a recessive mutant, termed defective in pollen organelle DNA degradation1 (dpd1), showing elevated levels of DNAs in both plastids and mitochondria, was isolated and characterized. DPD1 encodes a protein belonging to the exonuclease family, whose homologs appear to be found in angiosperms. Indeed, DPD1 has Mg²⁺-dependent exonuclease activity when expressed as ...
SEC8, a subunit of the putative Arabidopsis exocyst complex, facilitates pollen germination and competitive pollen tube growth....SEC8, a subunit of the putative Arabidopsis exocyst complex, facilitates pollen germination and competitive pollen tube growth....
Abstract: The exocyst, a complex of eight proteins, contributes to the morphogenesis of polarized cells in a broad range of eukaryotes. In these organisms, the exocyst appears to facilitate vesicle docking at the plasma membrane during exocytosis. Although we had identified orthologs for each of the eight exocyst components in Arabidopsis (Arabidopsis thaliana), no function has been demonstrated for any of them in plants. The gene encoding one exocyst component ortholog, AtSEC8, is expressed in pollen and vegetative tissues of Arabidopsis. Genetic studies utilizing an allelic series of six independent T-DNA mutations reveal a role for SEC8 in male gametophyte function. Three T-DNA insertions in SEC8 cause an absolute, male-specific transmission defect that can be complemented by expression of SEC8 from the LAT52 pollen promoter. Microscopic analysis shows no obvious abnormalities in the microgametogenesis of the SEC8 mutants, and the mutant pollen grains appear to respond to the signals that ...
PANNA: Bt-Corn Pollen from Iowa Fields Kills Monarch Caterpillars | Pesticide Action NetworkPANNA: Bt-Corn Pollen from Iowa Fields Kills Monarch Caterpillars | Pesticide Action Network
October 10, 2000. In August, Iowa State University scientists reported in the journal Oecologia that one kind of Bt-corn pollen naturally deposited on milkweeds in and near corn fields kills monarch butterfly caterpillars. This research confirms a laboratory study published in Nature last summer which showed that Bt-corn pollen is lethal to monarchs.. The Iowa scientists conducted three kinds of studies using two types of Bt corn marketed by Novartis Seeds: KnockOut, which contains a Bt gene named Event 176 and YieldGard with a Bt gene called Bt 11. KnockOut pollen typically contains more Bt toxin than YieldGard pollen. The three experiments were:. * To learn how much pollen caterpillars might be exposed to under field conditions, researchers counted pollen that fell on milkweeds, the favorite food of monarch caterpillars, within and near KnockOut, YieldGard and nonBt-corn plots.. * To assess mortality of caterpillars exposed to natural, field-deposited pollen, researchers placed caterpillars on ...
Pollen analysis, chronology and palaeomagnetism of three Late Weichselian sites in southern SwedenPollen analysis, chronology and palaeomagnetism of three Late Weichselian sites in southern Sweden
phdthesis{49014232-643e-4a99-964c-da745443d018, abstract = {Three sites, Torreberga in Skåne, Farslycke in Blekinge and Lake Bolmen in Småland, with Late Weichselian lake sediments were studied with respect to pollen analysis and palaeomagnetism. The chronologies are based on pollen stratigraphical correlations, radiocarbon dating and, for two of the sites, on a clay-varve chronology. The stratigraphies were correlated to the GRIP event stratigraphy and their ages are expressed in calendar years BP.,br/,,br, ,br/,,br, The pollen records compare well to the established Late Weichselian pollen stratigraphy for southern Sweden, and reflect the vegetation development from the deglaciation to the transition to the Holocene. The annual time-resolution of the varved clays has made it possible to calculate pollen accumulation rates based on actual sedimentation rates. The delayed onset of sedimentation in Torreberga implies that dead ice was present for at least 2000 years after the regional ...
INERIS - Institut National de lEnviRonnement Industriel et des RisqueS - Ability of Pollen Cytoplasmic Granules to Induce...INERIS - Institut National de l'EnviRonnement Industriel et des RisqueS - Ability of Pollen Cytoplasmic Granules to Induce...
Background: Grass pollen is one of the most important aeroallergens in Europe. It highly contributes to respiratory allergic diseases, mainly allergic rhinitis. In contact to water or airborne pollutants, pollen grains can release pollen cytoplasmic granules (PCGs) containing allergens. Because of their size (| 5 mu m), PCGs may penetrate deeper into the lungs to induce higher allergic responses, such as asthma. They have been associated with thunderstorm-related asthma. The aim of this study was to evaluate, with Brown Norway rats, the allergenic potential of isolated PCGs and to compare it with the allergenicity of whole timothy grass pollen. Methods: Rats were sensitized (day 0) and challenged (day 21), in controlled comparative conditions, with pollen grains (0.5 mg) or PCGs (4.5 x 10(7) and 0.5 mg). At day 25, blood samples, bronchoalveolar lavage fluid (BALF) and bronchial lymph node were collected. IgE and IgG1 levels in sera were assessed by ELISA. Alveolar cells, protein and cytokine
Allergenic airborne grass pollen in Szczecin, Poland.Allergenic airborne grass pollen in Szczecin, Poland.
Grass pollens are known as very potent aeroallergens. The aim of the studywas to analyse the grass pollen season in Szczecin (western Poland) in the years 2000-2003 and to establisha relationship between the meteorological conditions and the pollen counts of Poaceae. The meteorologicalparameters...
Accumulation and variability of maize pollen deposition on leaves of European Lepidoptera host plants and relation to release...Accumulation and variability of maize pollen deposition on leaves of European Lepidoptera host plants and relation to release...
Maize is wind-pollinated and releases prodigious quantities of pollen into the environment during anthesis [1]. In the case of genetically modified Bacillus thuringiensis (Bt) maize, this pollen also carries insecticidal Bt protein. Because non-target herbivores may feed on host plants dusted with Bt pollen-both within and around maize fields, this exposure and its subsequent effects must be evaluated to assess the risks associated with the cultivation of Bt maize.. Risks posed to non-target Lepidoptera by the cultivation of Bt maize plants resistant to lepidopteran species such as the European corn borer are widely acknowledged [2-5]. Scientific controversies exist, however, in regard to estimates of the potential magnitude of effects and measures such as isolation buffer distances applied for risk management [5-14].. Because exposure is the basis of any effect, the interpretation of maize pollen leaf deposition data is highly relevant to the above debate. For several reasons, successful ...
Pollen elicits proboscis extension but does not reinforce PER learning in honeybees : Sussex Research OnlinePollen elicits proboscis extension but does not reinforce PER learning in honeybees : Sussex Research Online
The function of pollen as a reward for foraging bees is little understood, though there is evidence to suggest that it can reinforce associations with visual and olfactory floral cues. Foraging bees do not feed on pollen, thus one could argue that it cannot serve as an appetitive reinforcer in the same way as sucrose. However, ingestion is not a critical parameter for sucrose reinforcement, since olfactory proboscis extension (PER) learning can be conditioned through antennal stimulation only. During pollen collection, the antennae and mouthparts come into contact with pollen, thus it is possible that pollen reinforces associative learning through similar gustatory pathways as sucrose. Here pollen was presented as the unconditioned stimulus (US), either in its natural state or in a 30% pollen-water solution, and was found to elicit proboscis extension following antennal stimulation. Control groups were exposed to either sucrose or a clean sponge as the US, or an unpaired presentation of the ...
FAQs About Timothy Grass Pollen Allergen Extract Tablet | GRASTEK®FAQs About Timothy Grass Pollen Allergen Extract Tablet | GRASTEK®
Allergic to grass? GRASTEK® is a prescription immunotherapy sublingual tablet for Timothy & related grass pollen allergies. View Safety Info & Boxed Warning.
20 Alternative Remedies For Hay Fever20 Alternative Remedies For Hay Fever
There are actually three hay fever seasons. Tree pollens appear first, usually between February and May, depending on the local climate. Then later in spring and summer there are both tree and grass pollens. Then in the fall is ragweed pollen season. Hay fever may be present at any or all of these times.. Although antihistamines are the most conventional treatment for hay fever, they can also cause drowsiness, depression and other undesirable side effects.. The best and safest way to control allergies is the natural way - by avoiding allergens, taking steps to normalize immune function and prevent or lessen the symptoms.. Ways to avoid allergens:. 1. Spend as little time outside as possible. Avoid the hours between 5:00 AM and 10:00 AM when pollen levels are at their highest. 2. Keep pets either inside or outside. Pets can pick up pollen on their fur and bring it indoors with them.. 3. Shower and change your clothes when you come indoors after spending time outside. Pollen can stick to your ...
Timothy grass pollen allergen extract | definition of timothy grass pollen allergen extract by Medical dictionaryTimothy grass pollen allergen extract | definition of timothy grass pollen allergen extract by Medical dictionary
Looking for online definition of timothy grass pollen allergen extract in the Medical Dictionary? timothy grass pollen allergen extract explanation free. What is timothy grass pollen allergen extract? Meaning of timothy grass pollen allergen extract medical term. What does timothy grass pollen allergen extract mean?
The Arabidopsis mutant feronia disrupts the female gametophytic control of pollen tube reception - CSHL Scientific Digital...The Arabidopsis mutant feronia disrupts the female gametophytic control of pollen tube reception - CSHL Scientific Digital...
Reproduction in angiosperms depends on communication processes of the male gametophyte (pollen) with the female floral organs (pistil, transmitting tissue) and the female gametophyte (embryo sac). Pollen-pistil interactions control pollen hydration, germination and growth through the stylar tissue. The female gametophyte is involved in guiding the growing pollen tube towards the micropyle and embryo sac. One of the two synergids flanking the egg cell starts to degenerate and becomes receptive for pollen tube entry. Pollen tube growth arrests and the tip of the pollen tube ruptures to release the sperm cells. Failures in the mutual interaction between the synergid and the pollen tube necessarily impair fertility. But the control of pollen tube reception is not understood. We isolated a semisterile, female gametophytic mutant from Arabidopsis thaliana, named feronia after the Etruscan goddess of fertility, which impairs this process. In the feronia mutant, embryo sac development and pollen tube ...
Pollen Germinability and Cross-Pollination Success in Persian Cyclamen (Cyclamen persicum Mill.)Pollen Germinability and Cross-Pollination Success in Persian Cyclamen (Cyclamen persicum Mill.)
Low seed yield is a limiting factor for cross breeding and hybrid seed production in cyclamen. This study was performed to investigate pollen germination and its relation to cross-pollination success and fruit set in this plant. In order to achieve a high level of pollen germination, the effect of different concentrations of chemical compounds were examined on in vitro pollen germination of cyclamen in modified Brewbaker and Kwack medium, containing sucrose (10 and 20%), calcium nitrate (0, 200 and 300 mg l-1), and boric acid (0, 100 and 200mg l-1 ) at two pH levels (5.5 and 6.5). Maximum pollen germination was obtained in media containing higher concentration of calcium and boron regardless of sucrose concentration and pH level. Pollen germination percentage was genotype-dependent. Cross-pollination was performed among four different genotypes characterized by various pollen germination percentages. There was a direct correlation between cross-pollination success and pollen germination percentage.
Interaction of the onset of spring and elevated atmospheric C[O.sub.2] on ragweed (Ambrosia artemisiifolia L.) pollen...Interaction of the onset of spring and elevated atmospheric C[O.sub.2] on ragweed (Ambrosia artemisiifolia L.) pollen...
Free Online Library: Interaction of the onset of spring and elevated atmospheric C[O.sub.2] on ragweed (Ambrosia artemisiifolia L.) pollen production.(Research) by Environmental Health Perspectives; Health, general Environmental issues Asthma Carbon dioxide Climate change Climatic changes
Arabidopsis FIMBRIN5, an Actin Bundling Factor, Is Required for Pollen Germination and Pollen Tube Growth | Plant CellArabidopsis FIMBRIN5, an Actin Bundling Factor, Is Required for Pollen Germination and Pollen Tube Growth | Plant Cell
In plants, the pollen tube extends rapidly via tip growth, thereby allowing the movement of two nonmotile sperm cells through the pistil for the purpose of double fertilization. Pharmacological disruption of actin and genetic manipulation of the actin regulatory system have revealed that the actin cytoskeleton is a major mediator of pollen tube growth (Gibbon et al., 1999; Chen et al., 2002; Cheung and Wu, 2004; Xiang et al., 2007). Furthermore, imaging of actin filaments has shown that distinct actin structures form in pollen tubes across different species. The consensus view is that actin filaments can be divided into at least three distinct structures in pollen tubes: longitudinal actin cables found in the shanks of pollen tubes; dense actin structures, such as collar-like structures or actin fringes, found at the subapexes; and highly dynamic, but less abundant, actin filaments found at the extreme tips (Kost et al., 1998; Fu et al., 2001; Lovy-Wheeler et al., 2005; Cheung et al., 2008; Chen ...
Frontiers | Organization and regulation of the actin cytoskeleton in the pollen tube | Plant ScienceFrontiers | Organization and regulation of the actin cytoskeleton in the pollen tube | Plant Science
Proper organization of the actin cytoskeleton is crucial for pollen tube growth. However, the precise mechanisms by which the actin cytoskeleton regulates pollen tube growth remain to be further elucidated. The functions of the actin cytoskeleton are dictated by its spatial organization and dynamics. However, early observations of the distribution of actin filaments at the pollen tube apex were quite perplexing, resulting in decades of controversial debate. Fortunately, due to improvements in fixation regimens for staining actin filaments in fixed pollen tubes, as well as the adoption of appropriate markers for visualizing actin filaments in living pollen tubes, this issue has been resolved and has given rise to the consensus view of the spatial distribution of actin filaments throughout the entire pollen tube. Importantly, recent descriptions of the dynamics of individual actin filaments in the apical region have expanded our understanding of the function of actin in regulation of pollen tube growth.
Long-Distance Transport of Ragweed Pollen to Southern Hungar... : EpidemiologyLong-Distance Transport of Ragweed Pollen to Southern Hungar... : Epidemiology
Three days (June 21, 1993; July 3, 2000; and July 6, 2003) were selected from the 15-year period of 1989 to 2003, for which ragweed pollen was detected, despite the fact that local pollen dispersion had not been started. Ragweed pollen of transported and local origin was separated so that ragweed pollen detected before flowering of local ragweed was considered as of transported origin. Then, backward trajectories belonging to the days of peak concentrations of this period (ie, those trajectories belonging to the 3 days selected) were examined for 3 and 7 days, respectively. For the 3 days selected, archive meteorological database was used and the HYSPLIT model was applied to calculate trajectories of ragweed pollen grains as well as to detect their source regions.. ...
Conditions - Advanced Allergy, Asthma, and Immunology Center of San Antonio | Dr. Patricia Gomez DingerConditions - Advanced Allergy, Asthma, and Immunology Center of San Antonio | Dr. Patricia Gomez Dinger
Pollen is the male fertilizing agent of flowering plants, trees, grasses and weeds. Pollen is a central cause of many allergic reactions. Weather conditions affect pollen levels. The most variant factors influencing different pollen counts from approximately the same region are wind, humidity, and the proximity of the sampling equipment to pollen producing vegetation. Because pollens are small, light and dry, they can be easily spread by wind, which keeps pollen airborne and carries it over long distances. When the air is humid, such as during or after it rains, pollen becomes damp and heavy with moisture, keeping it still and on the ground.. Mountain Cedar Pollen: Cedar trees, also known as juniper trees (officially called Juniperus ashei), are evergreens that are predominant in Texas, especially in the city of San Antonio. Peak pollen production is from December through February and release of pollen occurs between 5 a.m. and 10 a.m. Pollen counts are highest on warm, sunny days. The pollen is ...
Characterization of Arabidopsis thaliana pollen tube cell wall - Normandie UniversitéCharacterization of Arabidopsis thaliana pollen tube cell wall - Normandie Université
Flavien Dardelle, Arnaud Lehner, Yasmina Ramdani, Muriel Bardor, Patrice Lerouge, et al.. Characterization of Arabidopsis thaliana pollen tube cell wall. ASPB-CSPP Annual Plant Biology Meeting, Jul 2010, Montréal, Canada. ⟨hal-02127161⟩ ...
The major olive pollen allergen (Ole e I) shows both gametophytic and sporophytic expression during anther development, and its...The major olive pollen allergen (Ole e I) shows both gametophytic and sporophytic expression during anther development, and its...
The distribution of Ole e I (the major olive pollen allergen) and its transcripts was investigated in the anther from premeiotic stages until the dehiscent pollen stage. Crude protein extracts were analyzed by immunoblotting and probed with a monoclonal antibody to Ole e I. The protein, with three variants, was found to accumulate from the early microspore stage onwards. In addition to the previously reported localization of the protein, Ole e I has been immunolocalized for the first time within the pollen wall and in the tapetum. Reverse transcription-polymerase chain reaction analysis using specific oligonucleotides and RNA extracted from whole anthers revealed that the Ole e I gene is expressed from the late tetrad stage onwards. No expression was found in control tissues such as petals, roots or leaves. Light microscopy in situ hybridization on developing flower buds and dehiscent pollen confirmed the transcripts to be present in both the microspores and the sporophytic tissue (tapetum). ...
Frontiers | The Representativeness of Olea Pollen from Olive Groves and the Late Holocene Landscape Reconstruction in Central...Frontiers | The Representativeness of Olea Pollen from Olive Groves and the Late Holocene Landscape Reconstruction in Central...
Modern pollen spectra are an invaluable reference tool for paleoenvironmental and cultural landscape reconstructions, but the importance of knowing the pollen rain released from orchards remains underexplored. In particular, the role of cultivated trees is in past and current agrarian landscapes has not been fully investigated. Here, we present a pollen analysis of 70 surface soil samples taken from 12 olive groves in Basilicata and Tuscany, two regions of Italy that exemplify this cultivation in the Mediterranean basin. This study was carried out to assess the representativeness of Olea pollen in modern cultivations. Although many variables can influence the amount of pollen observed in soils, it was clear that most of the pollen was deposited below the trees in the olive groves. A rapid decline in the olive pollen percentages (c. 85% on average) was found when comparing samples taken from IN vs. OUT of each grove. The mean percentages of Olea pollen obtained from the archeological sites close to the
New evidence of long distance pollen transport to southern Greenland in late spring | Lamont-Doherty Earth ObservatoryNew evidence of long distance pollen transport to southern Greenland in late spring | Lamont-Doherty Earth Observatory
New observations of long-distance pollen transport to southern Greenland are recorded during the last 2 weeks of May, 2003. The results indicate northeastern North America as the source area of the transported pollen grains as shown in earlier investigations. Backward trajectories indicate that transport occurred twice during the first week corresponding to a time of maximum pollen flux emitted to the atmosphere in the source area. A large percentage of exotic pollen grains were identified, about 11% of the total counted. However, transport during the second week appears to have occurred during a single day at a time of reduced pollen emission into the atmosphere, which was subjected later to severe washout. As a result, only 1% of the total pollen spectra was identified as exotic grains. The back trajectories modeled by the HYSPLIT application differ somewhat from those previously identified in 2002. Although in both years air passing over southern Greenland at 3000 in carried out the main ...
The Asthma Center Education and Research Fund | Newsletter | Allergic rhinitisThe Asthma Center Education and Research Fund | Newsletter | Allergic rhinitis
Tree pollen begins in the early spring (see graph above). Common tree pollen in the Delaware Valley include oak, juniper, cedar, elm, sycamore, pine, walnut and mulberry. There may be more than one tree season each year (spring and fall for elm or pine pollen). Each tree pollen allergen is unique. Most people allergic to a few specific tree pollen are not bothered by others.. Grass pollen occurs mostly between April and June in the Delaware Valley. Common grass pollen include Timothy, Kentucky Blue, and Rye grass. Bermuda grass is not prominent in our area. Grass pollen share many common allergens and most people allergic to a specific grass will have problems with most grass pollen.. Weed pollen common to our area include ragweed, sheep sorrel, yellow dock, sage, urtica, lambs quarters, and English plantain. Weeds pollinate from midsummer through the fall. Ragweed is a very common and potent pollen east of the Rocky Mountains that causes severe symptoms in many patients between mid-August and ...
Calcium Channel Activity during Pollen Tube Growth and Reorientation. | Plant CellCalcium Channel Activity during Pollen Tube Growth and Reorientation. | Plant Cell
We have shown previously that the inhibition of pollen tube growth and its subsequent reorientation in Agapanthus umbellatus are preceded by an increase in cytosolic free calcium ([Ca2+]c), suggesting a role for Ca2+ in signaling these processes. In this study, a novel procedure was used to measure Ca2+ channel activity in living pollen tubes subjected to various growth reorienting treatments (electrical fields and ionophoretic microinjection). The method involves adding extracellular Mn2+ to quench the fluorescence of intracellular Indo-1 at its ca2+-insensitive wavelength (isosbestic point). The spatial and temporal kinetics of Ca2+ channel activity correlated well with measurements of [Ca2+]c dynamics obtained by fluorescence ratio imaging of Indo-1. Tip-focused gradients in Ca2+ channel activity and [Ca2+]c were observed and quantified in growing pollen tubes and in swollen pollen tubes before reoriented growth. In nongrowing pollen tubes, Ca2+ channel activity was very low and [Ca2+]c ...
The Differences Between Male Pollen & Female Seed Pine Cones | SciencingThe Differences Between Male Pollen & Female Seed Pine Cones | Sciencing
When the male pine cone releases its pollen, breezes and winds carry the pollen to another pine tree. Here the pollen can become caught between the central stem of the female cone and a megasporophyll. This is pollination. The pollen then produces a pollen tube, which grows into the female megasporangium, also called an ovule. The process can take over a year. When the tube has formed, sperm moves down the tube from the pollen to the female egg. This is fertilization. The fertilized egg will produce an embryo. The embryo will be enclosed in a seed case made up of part of the megasporophyll. The seed case will have a small wing that will help the wind disperse it effectively. As soon as the seed is mature, the female cone will open to release it. Many pollen grains pollinate and fertilize many female eggs at the same time in a female pine cone.. ...
Molecular cloning of the mountain cedar (Juniperus ashei) pollen major allergen, Jun a 1<...Molecular cloning of the mountain cedar (Juniperus ashei) pollen major allergen, Jun a 1<...
TY - JOUR. T1 - Molecular cloning of the mountain cedar (Juniperus ashei) pollen major allergen, Jun a 1. AU - Midoro-Horiuti, Terumi. AU - Goldblum, R. M.. AU - Kurosky, A.. AU - Wood, Thomas. AU - Schein, C. H.. AU - Brooks, E. G.. PY - 1999. Y1 - 1999. N2 - Background: Cedar pollens cause allergic disease in diverse geographic areas. We have recently purified and characterized the major mountain cedar (Juniperus ashei) pollen allergen, Jun a 1. Objective: A full-length complementary DNA for Jun a 1 was cloned and sequenced, and the recombinant protein was expressed. Methods: Messenger RNA from mountain cedar pollen was purified and Jun a 1 sequences were established with use of reverse transcriptase-PCR and primers based on the N-terminal amino acid sequence of Jun a 1 and the homologous protein Cry j 1. Portions of the nucleotide sequence were confirmed by comparison with N-terminal amino acid sequencing of the intact tryptic fragments of the purified native protein. Recombinant Jun a 1 was ...
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Nasal AMP and histamine challenge within and outside the pollen season in patients with seasonal allergic rhinitis - Research...Nasal AMP and histamine challenge within and outside the pollen season in patients with seasonal allergic rhinitis - Research...
TY - JOUR. T1 - Nasal AMP and histamine challenge within and outside the pollen season in patients with seasonal allergic rhinitis. AU - Vaidyanathan,Sriram. AU - Williamson,Peter. AU - Clearie,Karine. AU - Morrison,Ashley. AU - Lipworth,Brian. PY - 2011/1. Y1 - 2011/1. N2 - Background: Nasal hyperreactivity is a prominent feature of allergic rhinitis. Variation in nasal hyperreactivity with different challenge agents in and out of the pollen season has not been examined.Objective: We sought to compare nasal hyperreactivity with different challenge agents before, during, and after the pollen season.Methods: Grass pollen-monosensitized patients performed cumulative-dose challenges with nasal AMP (25-800 mg . mL(-1)) and histamine (0.25-8 mg . mL(-1)) before, during, and after the grass pollen season. Outcomes included the provocative concentration of agent causing a 30% decrease in the peak nasal inspiratory flow (PNIF) (PC30), recovery profile, and diary cards.Results: Nineteen participants ...
Asian Science Citation Index - Articles written by Abdul Ghani AwanAsian Science Citation Index - Articles written by Abdul Ghani Awan
Pollen morphology of two different species, Tragopogon dubius and Tragopogon gracilis, belonging to genus Tragopogon of family Asteraceae was studied from Pakistan. Morphology of pollen grains of each of the species is based on specimens selected at random. Proposed characters i.e. grain, shape of pollen grain, equatorial view, polar view, equatorial diameter (E), polar diameter (P), P / E ratio, length of colpus, exine surface, exine thickness, inter poral distance, inter spinal distance, inter spinal outline, length of spines, number of spines between colpi in each species were recorded for comparison. At species level, micromorphological differences and distribution of surface pattern, shape and size of pollen have been found to exist. The pollen grains are consistently echinate, trizonocolporate but in Tragopogon dubius pollen grains are tetrazonocolporate. Maximum, equatorial view, polar view, equatorial diameter (E), polar diameter (P), P/ E ratio, length of colpus, exine surface, exine ...
Varying Sugars and Sugar Concentrations Influence In Vitro Pollen Germination and Pollen Tube Growth of Cassia alata L. -...Varying Sugars and Sugar Concentrations Influence In Vitro Pollen Germination and Pollen Tube Growth of Cassia alata L. -...
This study investigates the effects of varying sugars and sugar concentrations on the in vitro germination and tube growth of pollens of Cassia alata L., a known Philippine ornamental and medicinal plant. This aims to add information on the pollination fertilization mechanism of the plant for its possible extensive cultivation.
Maple pollen - 3D model by 3D Pollen Project (@3dpollenproject) [d6b2a55] - SketchfabMaple pollen - 3D model by 3D Pollen Project (@3dpollenproject) [d6b2a55] - Sketchfab
Pollen from field maple (Acer campestre, Sapindaceae). Some maple species can be major early-season pollen producers, making them important for bees. Technical description of Acer campestre pollen, from PalDat (Hesse & Halbritter, 2016): medium-sized isopolar monads, spheroidal or prolate, circular or lobate in polar view, tricolpate, with a striate exine. This model is part of the 3D Pollen Project. For more information, including how to download this file, see https://3dpollenproject.wixsite.com/main/downloads - Maple pollen - 3D model by 3D Pollen Project (@3dpollenproject) [d6b2a55]
On the fast lane: mitochondria structure, dynamics and function in growing pollen tubes. | Pollen RCNOn the fast lane: mitochondria structure, dynamics and function in growing pollen tubes. | Pollen RCN
The structure, distribution and possible roles of mitochondria in growing pollen tubes is reviewed. Diverse microscopical methods have been applied to the analysis of mitochondria in pollen, with a predominance in recent years on vital fluorescent probes. We review the application of different dyes to pollen tubes, with a special emphasis on the ratiometric dye JC-1. Morphometric data shows a concentration of mitochondria in the subapical area of pollen tubes, apparently with more frequency of mitochondria with membrane depolarization when compared with the rest of the tube. Remarkably, data from various species and from transcriptomics indicates that different species may have different respiratory adaptations, ranging from high oxygen consumption in the early steps of germination, to energy production and growth on almost anoxic conditions. Various studies also showed that the pollen of many species is refractory to some common respiration inhibitors, including the ones from the alternative ...
TORII PHARMACEUTICAL|Investor Relations|Press ReleasesTORII PHARMACEUTICAL|Investor Relations|Press Releases
Japanese cedar pollinosis collectively refers to an allergic disease caused by Japanese cedar pollen. Patients with Japanese cedar pollinosis primarily have allergic rhinitis and allergic conjunctivitis. Patients develop sneezing and nasal discharge immediately after Japanese cedar pollens enter their nose, and have nasal occlusion after a while. Also, when Japanese cedar pollens enter their eyes, they have itchy, runny and bloodshot eyes. When the symptoms are strong, antigen components of pollens not absorbed in the nose may flow from the nose to the throat, causing itchiness of the throat and coughing. Further, symptoms such as headache due to nasal occlusion, slight fever due to inflammatory reactions in the nose and the throat, and dullness may occur ...
Pollen Allergy Sufferers Reach for Raw Honey for Relief - Artificial Intelligence SEO . comPollen Allergy Sufferers Reach for Raw Honey for Relief - Artificial Intelligence SEO . com
United States (PRWEB) May 04, 2013 As the spring pollen season ratchets up so has the demand for raw honey at the Mohawk Valley Trading Company.. Raw wildflower honey is often used by pollen allergy sufferers to lessen their sensitivity to pollen by eating 1 to 2 teaspoons of it each day. said Mary Ross of the Mohawk Valley Trading Company where they specialize in raw varietal honey. Varietal honey is made primarily from the nectar of a particular type of blossom or flower. To capture the unique character and flavor of the blossom or flower, beekeepers must study botanical bloom and flowering patterns when planning hive placement. The idea is that by introducing small amounts of pollen into their system by eating raw honey, a tolerance to pollen allergens is built up.. Honey has been used by humans since ancient times for its health benefits and as a sweetener and flavoring for many foods and beverages, with tea being the most popular. Next to maple syrup, it is the most commonly used natural ...
Andalusia, Home of Flannery OConnor: Puddles of PollenAndalusia, Home of Flannery O'Connor: Puddles of Pollen
Until yesterdays rain, Andalusia was blanketed in a haze of pine pollen. Even the bright red roof of the main house was covered with the yellow powder. For those of us who have lived in middle Georgia for a while, the arrival of the pine pollen signals the beginning of long, mild spring days and, for some, sniffles and sneezes. Maybe it has something to do with the wet, cold winter we had, but most locals cant remember the pollen being this heavy. Fortunately, yesterdays rain cleaned the air, slaked parched gardens, and created puddles of yellow pollen on the ground. Today the lines at the local car washes will be pretty long as midstaters rinse the pollen off their vehicles that the rain didnt. After you get your car washed, why not consider decorating it with one of our brand new bumper stickers? These one of a kind items are only $4 each and are available for purchase in the Andalusia gift shop or by phone order ...
Pollen tube growth questionPollen tube growth question
The pollen tube is the extension of a single cell of the pollen grain , (or male gametophyte) the tube cell. You can demonstrate that this , growth does not require any contribution of the style other than , sucrose, calcium, and boron, since pollen grains of many species will , successfully germinate in a liquid medium containing these three , ingredients. If Growth does imply also -tropism, then there must be factor/s other than the sucrose, calcium and boron. For the pollen tube does grow dirrectly towards the ovules ...
Characterization of Phl p 4, a major timothy grass (Phleum pratense) pollen allergen. - literature database - CNGBdbCharacterization of Phl p 4, a major timothy grass (Phleum pratense) pollen allergen. - literature database - CNGBdb
Group 4 grass pollen allergens represent glycoproteins with a molecular weight of 50 to 60 kd, which are present in many grass species. Almost 75% of patients allergic to grass pollen display IgE reac...
Pollen extracts increase growth of a trypanosome parasite of bumble bees [PeerJ Preprints]Pollen extracts increase growth of a trypanosome parasite of bumble bees [PeerJ Preprints]
Phytochemicals produced by plants, including at flowers, function in protection against plant diseases, and have a long history of use against trypanosome infection. Floral nectar and pollen, the sole food sources for many species of insect pollinators, contain phytochemicals that have been shown to reduce trypanosome infection in bumble and honey bees when fed as isolated compounds. Nectar and pollen, however, consist of phytochemical mixtures, which can have greater antimicrobial activity than do single compounds. This study tested the hypothesis that pollen extracts would inhibit parasite growth.Extracts of six different pollens were tested for direct inhibitory activity against cell cultures of the bumble bee trypanosome gut parasite Crithidia bombi. Surprisingly, pollen extracts increased parasite growth rather than inhibiting it. Experimental manipulations of growth media showed that supplemental monosaccharides (glucose and fructose) were sufficient to promote growth, while a common floral
Effects of Flavonoids on Pollen Tube Growth in Arabidopsis thalianaEffects of Flavonoids on Pollen Tube Growth in Arabidopsis thaliana
Arabidopsis mutants deficient in flavonoid and sinapate ester (tt4 and fah1-7, respectively) were evaluated in vivo and in vitro to study the possible role of flavonoid compounds in pollen tube growth. In vivo, we investigated pollen tube growth in the pistils of the mutants and wild type(Ler). The ...
Ongoing seasonal intestinal inflammation in birch pollen allergic patients without gastrointestinal symptoms | Clinical and...Ongoing seasonal intestinal inflammation in birch pollen allergic patients without gastrointestinal symptoms | Clinical and...
All patients were clinically diagnosed as birch pollen allergic. Seven patients allergic to birch pollen without any gastrointestinal symptoms and seven completely healthy individuals were included in the study for comparison. All patients were examined with a standard skin prick test panel and blood samples were analysed for IgE antibodies by component micro-arrays (ISAC). The two groups of patients underwent gastroscopy and duodenal biopsies were taken both during (May-June) and outside the pollen season (November-January) for each patient. Duodenal biopsies were examined with immunostaining for mast cells (IgE and tryptase), eosinophils (eosinophil peroxidase), T-cells (CD3), and dendritic cells (DC) (CD11c). ...
Plant Reproductive Biology | Minnesota Supercomputing InstitutePlant Reproductive Biology | Minnesota Supercomputing Institute
The goal of this research is to elucidate the mechanisms by which the transmitting tissue (TT) regulates pollen tube growth. Plant arbinogalactan proteins (AGPs) are a large family of complex structural proteins known to regulate root development and pollen tube growth. The TT-specific AGPs that are the focus of this project include the Transmitting Tissue Specific (TTS) and the Class III Pistil Extensin-Like Protein (PELPIII). They are developmentally regulated, highly glycosylated, taken up by pollen tubes, and composed of conserved proline-rich N-terminal (NTD) and cysteine-rich C-terminal domains (CTD). The Nicotiana tabacum PELPIII was shown to be essential for specific inhibition of pollen tube growth during interspecific incompatibility; TTS protein promotes pollen tube growth in vivo and in vitro; 120-kDa (120K) protein is required for Nicotiana alata S-specific pollen rejection. Although the AGPs regulate pollen tube growth and are, therefore, involved in species evolution, the ...
Pollen Power! Summer Camp | Carl R. Woese Institute for Genomic BiologyPollen Power! Summer Camp | Carl R. Woese Institute for Genomic Biology
Hosted by the Carl R. Woese Institute for Genomic Biology on the University of Illinois campus, Pollen Power! provides an opportunity for girls to study plant responses to climate change in the distant past and the coming century. Research groups of 8 to 10 campers, led by female graduate students, use million-dollar microscopes to image pollen, providing campers with first-hand experience working with female mentors in a research environment. Campers also investigate pollen as a time capsule to study the climate that existed millions of years ago, identify ancient pollen, watch pollen germinate in real-time, and tour the state-of-the art research labs and facilities on campus.. The camp is designed for middle-school-age girls with an interest in plants and the environment. Visit the Pollen Power! website to learn more.. ...
Cold-induced repression of the rice anther-specific cell wall invertase gene OSINV4 is correlated with sucrose accumulation and...Cold-induced repression of the rice anther-specific cell wall invertase gene OSINV4 is correlated with sucrose accumulation and...
TY - JOUR. T1 - Cold-induced repression of the rice anther-specific cell wall invertase gene OSINV4 is correlated with sucrose accumulation and pollen sterility. AU - Oliver, Sandra N.. AU - Van Dongen, Joost T.. AU - Alfred, Sanjeev C.. AU - Mamun, Ezaz A.. AU - Zhao, Xiaochun. AU - Saini, Hargurdeep S.. AU - Fernandes, Sussan F.. AU - Blanchard, Christopher L.. AU - Sutton, Bruce G.. AU - Geigenberger, Peter. AU - Dennis, Elizabeth S.. AU - Dolferus, Rudy. PY - 2005/12/1. Y1 - 2005/12/1. N2 - Low temperatures during rice (Oryza sativa L.) pollen development cause pollen sterility and decreased grain yield. We show that the time of highest sensitivity to cold coincides with the time of peak tapetal activity: the transition of the tetrad to early uni-nucleate stage (young microspore, YM stage). Low temperatures at this stage of pollen development result in an accumulation of sucrose in the anthers, accompanied by decreased activity of cell wall bound acid invertase and depletion of starch in ...
Pine Pollen Powder - See the Full Review Article About the Pine Pollen Product.. - GraceleeprojectPine Pollen Powder - See the Full Review Article About the Pine Pollen Product.. - Graceleeproject
Pine plant pollen can be a potent herbal extracted from a pine plant. A lot of people and corporations make your natural powder out of the plant pollen. This makes it easier for customers to bring it. There are numerous advantages that include pine pollen.. A couple of the favorite Phyto-androgens are Gibberellins and brassinosteroids. Gibberellins are exactly like androgenic hormone or testosterone in construction and they are greatly used in the first stages of germination. Professionals have realized out that Gibberellins mirror testosterone as a result activate the creation of androgen. The Phyto androgens have also been found to regulate the activity on the prostate. The sterol element of gibberellins oversees the size of the prostate. In case the prostate is way too large, it decreases and the other way around. The brassinosteroids aid in taking away xenobiotic materials in the liver hence maintaining you far healthier.. The merchandise is not only well suited for gentlemen-its also ...
Plants | Free Full-Text | Regulation of Pollen Tube Growth by Transglutaminase | HTMLPlants | Free Full-Text | Regulation of Pollen Tube Growth by Transglutaminase | HTML
In pollen tubes, cytoskeleton proteins are involved in many aspects of pollen germination and growth, from the transport of sperm cells to the asymmetrical distribution of organelles to the deposition of cell wall material. These activities are based on the dynamics of the cytoskeleton. Changes to both actin filaments and microtubules are triggered by specific proteins, resulting in different organization levels suitable for the different functions of the cytoskeleton. Transglutaminases are enzymes ubiquitous in all plant organs and cell compartments. They catalyze the post-translational conjugation of polyamines to different protein targets, such as the cytoskeleton. Transglutaminases are suggested to have a general role in the interaction between pollen tubes and the extracellular matrix during fertilization and a specific role during the self-incompatibility response. In such processes, the activity of transglutaminases is enhanced, leading to the formation of cross-linked products (including
Pine pollen not the cause of spring allergies | BrunswickBeacon.comPine pollen not the cause of spring allergies | BrunswickBeacon.com
Pine pollen may be coating sidewalks and cars with yellow dust, but it is not to blame for making people sneeze. People suffer from pollen allergies, but pine pollen doesnt contribute to it. The chemical composition of pine pollen appears to make it less allergenic than other types. Because pine pollen is heavy, it tends to fall straight down, and does not scatter easily in the wind; therefore, it rarely reaches human noses.
Cytoplasmic male sterility - WikipediaCytoplasmic male sterility - Wikipedia
Cytoplasmic male sterility is total or partial male sterility in plants as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure of plants to produce functional anthers, pollen, or male gametes The first documentation of male sterility was by Joseph Gottlieb Kölreuter, who observed anther abortion within species and specific hybrids. Cytoplasmic male sterility has now been identified in over 150 plant species. It is more prevalent than female sterility, either because the male sporophyte and gametophyte are less protected from the environment than the ovule and embryo sac, or because it results from natural selection on mitochondrial genes which are maternally inherited and are thus not concerned with pollen production. Male sterility is easy to detect because a large number of pollen grains are produced and are easily studied. Male sterility is assayed through staining techniques (carmine, lactophenol or iodine), while detection of female sterility is by ...
Bee Pollen Products | Indigo HerbsBee Pollen Products | Indigo Herbs
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Pollen Morphology and Systematic Relationship of the Family Polygonaceae. 1997. 11 microscop. plates. V, 104 p. gr8vo....Pollen Morphology and Systematic Relationship of the Family Polygonaceae. 1997. 11 microscop. plates. V, 104 p. gr8vo....
Pollen Morphology and Systematic Relationship of the Family Polygonaceae. 1997. 11 microscop. plates. V, 104 p. gr8vo. Hardcover. ...
A ragweed pollen as a treatment for a ragweed allergy? It s called immunotherapy. - PDFA ragweed pollen as a treatment for a ragweed allergy? It s called immunotherapy. - PDF
A ragweed pollen as a treatment for a ragweed allergy? It s called immunotherapy. RAGWITEK is a prescription medicine used for sublingual (under the tongue) immunotherapy to treat ragweed pollen allergies
Ragweed Pollen Season Lengthens | GlobalChange.govRagweed Pollen Season Lengthens | GlobalChange.gov
Ragweed pollen season length has increased in central North America between 1995 and 2011 by as much as 11 to 27 days in parts of the U.S. and Canada in response to rising temperatures. Increases in the length of this allergenic pollen season are correlated with increases in the number of days before the first frost. As shown in the figure, the largest increases have been observed in northern cities. (Data updated from Ziska et al. 20112d1ffd71-6c31-4d2e-9867-bdf330be45c1; Photo credit: Lewis Ziska, USDA).
CBD for Pollen Allergies | CBG Can Fight Your Pollen AllergiesCBD for Pollen Allergies | CBG Can Fight Your Pollen Allergies
The conventional line of treatment for pollen allergies are the OTC drugs, decongestants if your nose gets blocked or stuffy CBD for Pollen Allergies
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Allium crenulatumAllium crenulatum
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HernandiaceaeHernandiaceae
AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesTechnology, Industry, AgricultureHealth Care
PollenPollen TubePollinationRhinitis, Allergic, SeasonalLiliumBetulaAllergensFlowersAntigens, PlantAmbrosiaCupressusCryptomeriaPlant ProteinsGerminationOvulePlant InfertilitySelf-Incompatibility in Flowering PlantsAlnusOleaSeedsMeteorological ConceptsArabidopsisPoaceaeCedrusReproductionPapaverAngiospermsBeesTreesGametogenesis, PlantGene Expression Regulation, PlantImmunoglobulin EBetulaceaeArabidopsis ProteinsCupressaceaePlants, Genetically ModifiedPhleumSelf-FertilizationGerm Cells, PlantHypersensitivityGenes, PlantZea maysSkin TestsJuniperusDesensitization, ImmunologicSeasonsHoneyWindPetuniaFraxinusBrassicaArtemisiaLoliumTobaccoGametogenesis
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AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesTechnology, Industry, AgricultureHealth Care
PollenPollen TubePollinationRhinitis, Allergic, SeasonalLiliumBetulaAllergensFlowersAntigens, PlantAmbrosiaCupressusCryptomeriaPlant ProteinsGerminationOvulePlant InfertilitySelf-Incompatibility in Flowering PlantsAlnusOleaSeedsMeteorological ConceptsArabidopsisPoaceaeCedrusReproductionPapaverAngiospermsBeesTreesGametogenesis, PlantGene Expression Regulation, PlantImmunoglobulin EBetulaceaeArabidopsis ProteinsCupressaceaePlants, Genetically ModifiedPhleumSelf-FertilizationGerm Cells, PlantHypersensitivityGenes, PlantZea maysSkin TestsJuniperusDesensitization, ImmunologicSeasonsHoneyWindPetuniaFraxinusBrassicaArtemisiaLoliumTobaccoGametogenesis
AllergensAllergySpeciesAllergiesGrainGametophyteFlowering plantsPollinationSporesArabidopsisAntherViabilitySperm cellsBeesVitroProduce pollenAirborne pollenWeedsProteinsGerminationSymptomsGenerative2017HiveFlower PollenReproductivePlantVegetativeTubeCollect pollenHighest pollenMaize pollen depositionExposureHaploidParticlesGametes
Allergens3
Allergy8
Species12
  • Our investigation of pollen grains from across the plant kingdom further showed that microgel formation occurs with tested pollen species from eudicot plants. (nature.com)
  • Common features of pollen grains across various plant species include a microcapsule structure, function-driven shape, and ornamental architecture 12 . (nature.com)
  • In addition, each spore or pollen grain type is morphologically unique to its plant species. (tshaonline.org)
  • A few months later, other species of pollen-producing weeds and shrubs mature. (tshaonline.org)
  • In late summer and early fall, ragweeds and other species of grasses fill the Texas air with new types of pollen. (tshaonline.org)
  • In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. (le.ac.uk)
  • Filter bursting was directly compared with chopping in five species, yields were compared with published values for sonicated samples, and the method was applied by comparing genome size estimates for leaf and pollen nuclei in six species. (usda.gov)
  • In 41 % of species we met the most stringent criterion of screening 10 000 pollen grains per sample. (usda.gov)
  • Species Specificity in Pollen-Pistil Interactions" by Rob Swanson, Anna F. Edlund et al. (valpo.edu)
  • Although the pistil is a great facilitator of pollen function, it can also be viewed as an elaborate barrier that shields ovules from access from inappropriate pollen, such as pollen from other species. (valpo.edu)
  • In vitro pollen germination has been investigated at the genetic, physiological and biochemical levels in different plant species. (oeno-one.eu)
  • stated that gibberellins had an influence on pollen germination in seeded vine species. (oeno-one.eu)
Allergies13
Grain3
  • Pollen grains germinate on the surface of the stigma in the flower by forming a pollen tube which usually emerges through one of the apertures in the pollen grain wall. (le.ac.uk)
  • During pollen development each product of meiosis undergoes a stereotypical pattern of cell divisions to give rise to a three-celled gametophyte, the pollen grain. (biologists.org)
  • 1991 ) Differential effects of specific chromosomal deficiencies on the development of the maize pollen grain. (biologists.org)
Gametophyte1
  • In technical terms, pollen is the microscopic mature or immature multinucleate gametophyte generation of seed plants. (tshaonline.org)
Flowering plants1
Pollination3
  • Wind pollination is a successful strategy for many plants, and pollen can be transported over long distances. (springeropen.com)
  • However, it is important to distinguish between work carried out on gene flow (including cross pollination) and that carried out on pollen deposition itself. (springeropen.com)
  • For pollination to succeed, pollen must carry sperm through a variety of different floral tissues to access the ovules within the pistil. (valpo.edu)
Spores8
Arabidopsis5
Anther2
  • Pollen is produced in compartments termed locules, which reside within the anther. (cpib.ac.uk)
  • Pollen release occurs as a result of an anther dehiscence process, during which the anther wall splits, exposing the pollen to the environment. (cpib.ac.uk)
Viability5
  • Preliminary studies on pollen production and viability in wild relatives and cultivated cassava. (www.gov.uk)
  • However, little is known about the viability and other characteristics of pollen within wild and cultivated cassava germplasm. (www.gov.uk)
  • To fully understand the breeding potential of triploid herbaceous peony cultivars, and to promote the development of new peony cultivars and extend their culture in China, three triploid cultivars, 'Brightness', 'Roselette' and 'Coral Sunset', were selected to investigate their pollen viability and fertility. (ishs.org)
  • Our results show that pollen viability of the three triploid cultivars was very low, being highest (6.7%) in 'Brightness' and lowest (2.2%) in 'Coral Sunset', and that the pollen grains of the three triploid cultivars had a very low germination rate on the maternal stigma, caused by very short pollen tubes that could not penetrate the stigma. (ishs.org)
  • showed increasing and decreasing effect of 0.01 µM 24-epibrassinolide on pollen viability and germination. (oeno-one.eu)
Sperm cells2
  • Pollen is a remarkable natural material that plays a critical role in plant reproduction and transfers viable cellular material (i.e., male gametes or sperm cells) between different reproductive parts of plants 1 , 2 . (nature.com)
  • The two sperm cells are then transported within the pollen tube and delivered to the embryo sac inside the ovule to allow fertilisation to occur. (le.ac.uk)
Bees4
Vitro5
  • Indeed, DPD1 has Mg²⁺-dependent exonuclease activity when expressed as a fusion protein and when assayed in vitro and is highly active in developing pollen. (le.ac.uk)
  • In this study, the effects of two brassinosteroid compounds, epibrassinolide and 22S,23S-homobrassinolide, and gibberellic acid (GA 3 ) on in vitro pollen germination of two table grape cultivars, 'Italia' and 'Cardinal' ( Vitis vinifera L.), were determined. (oeno-one.eu)
  • Pollen germination evaluated in vitro might validate germination in vivo ( Hormaza and Herrero, 1999 ). (oeno-one.eu)
  • Literature on in vitro pollen germination of horticultural crops is abundant with studies determining basic medium constituents including boric acid, mineral salts or plant growth regulators. (oeno-one.eu)
  • This study was conducted to determine the effects of two brassinosteroid compounds, epibrassinolide and 22S,23S-homobrassinolide, along with the other growth regulator group, gibberellins, on in vitro pollen germination and growth of grapevine cultivars. (oeno-one.eu)
Produce pollen1
  • Some of these plants produce pollen that causes very uncomfortable reactions in humans commonly refereed to as hay fever. (redferret.net)
Airborne pollen4
Weeds1
Proteins2
Germination9
Symptoms2
Generative2
  • Both pollen types possess a large vegetative cell containing within, a single generative cell (bicellular pollen) or sperm cell pair (tricellular pollen). (le.ac.uk)
  • 1953 ) The role of the vegetative nucleus in pollen tube growth and in the division of the generative nucleus in Tradescantia paludosa . (biologists.org)
20172
  • One group ( n = 20) received mechanical PBL (PMBL-Ismigen ® , Lallemand Pharma AG, Switzerland) (group P) during the grass pollen season, sublingually for 10 consecutive days per month for 3 consecutive months (May, June and July 2017). (termedia.pl)
  • The pollen season in Lublin started on 19 May 2017 and ended on 12 August 2017. (termedia.pl)
Hive1
Flower Pollen2
  • Swedish flower pollen promotes healthy urine flow and helps maintain normal prostate cell function. (allstarhealth.com)
  • Woodland Scenics - Pollen 1oz Pack Yellow - Use this paper flower pollen to add. (craftonline.com.au)
Reproductive1
  • Collectively, our experimental and computational results offer fundamental insights into how tuning pollen structure can cause dramatic alterations to material properties, and inspire future investigation into understanding how the material science of pollen might influence plant reproductive success. (nature.com)
Plant9
  • It involves one or several characters becoming infected with a pollen of some alien or magical plant, or they might be influenced in some other way (magic, alien technology, mind control , etc.) that causes them to lose inhibitions and/or revs up libido, usually resulting in non-con sex, which may lead to dramatic guilt and misunderstandings, or a resolution of UST . (fanlore.org)
  • Dick is exposed to actual plant-based sex pollen and jumps Tim, because who wouldn't. (fanlore.org)
  • Pollen is the equivalent of sperm for a plant. (healthtap.com)
  • The reaction is usually from cross-sensitivity between a particular pollen and another plant. (healthtap.com)
  • Risk assessment for GMOs such as Bt maize requires detailed data concerning pollen deposition onto non-target host-plant leaves. (springeropen.com)
  • A field study of pollen on lepidopteran host-plant leaves was therefore undertaken in 2009-2012 in Germany. (springeropen.com)
  • The plant-specific pollen deposition data were supplemented with standardised measurements of pollen release rates and deposition obtained by volumetric pollen monitors and passive samplers. (springeropen.com)
  • Counting of the germinated pollens revealed that the effects of these plant hormones were cultivar- and substance-specific. (oeno-one.eu)
  • Pollens of the table grape cultivars 'Italia' and 'Cardinal' ( Vitis vinifera L.) were used as plant materials. (oeno-one.eu)
Vegetative1
  • The vegetative cell which comprises the bulk of the pollen cytoplasm is responsible for the development of the pollen tube. (le.ac.uk)
Tube2
  • The aperture gap in the exine layer is integral to pollen tube growth and is neighbored by pollen wall regions with distinct material properties. (nature.com)
  • The pistil provides everything the pollen requires for success in this endeavor including distinct guidance cues and essential nutrients that allow the pollen tube to traverse enormous distances along a complex path to the unfertilized ovule. (valpo.edu)
Collect pollen1
  • On the other hand, different bee colonies collect pollen from different plants and thus the reaction may not be universal. (healthtap.com)
Highest pollen1
  • The highest pollen deposition was within the field, but depositions of several thousand pollen grains per square meter were recorded over the kilometer range. (springeropen.com)
Maize pollen deposition2
  • We analyzed data on maize pollen deposition at 216 sites in Germany, Switzerland, and Belgium from 2001 to 2010. (springeropen.com)
  • Maize pollen deposition was negatively correlated with distance from the nearest pollen source. (springeropen.com)
Exposure5
  • A power function model most accurately described the relationship between deposition and distance from the nearest pollen source, rather than the exponential model currently used in EU risk assessment and management, which underestimates exposure for distances greater than 10 m. (springeropen.com)
  • Because pollen grains are carried by wind into the surrounding landscape, quantitative data on pollen deposition are needed to estimate the exposure of non-target organisms that may consume the pollen deposited on their host plants. (springeropen.com)
  • Because variation and total aggregation of deposited pollen on leaves have been previously underestimated, lepidopteran larvae have actually been subjected to higher and more variable exposure. (springeropen.com)
  • Because non-target herbivores may feed on host plants dusted with Bt pollen-both within and around maize fields, this exposure and its subsequent effects must be evaluated to assess the risks associated with the cultivation of Bt maize. (springeropen.com)
  • Because exposure is the basis of any effect, the interpretation of maize pollen leaf deposition data is highly relevant to the above debate. (springeropen.com)
Haploid1
Particles3
Gametes1
  • Background and Aims Flow cytometry has been used to measure nuclear DNA content in pollen, mostly to understand pollen development and detect unreduced gametes. (usda.gov)