Cupriavidus
Pulvinus
Burkholderia
Agricultural Inoculants
Radiometric Dating
Ralstonia
Legume symbiotic nitrogen fixation by beta-proteobacteria is widespread in nature. (1/48)
Following the initial discovery of two legume-nodulating Burkholderia strains (L. Moulin, A. Munive, B. Dreyfus, and C. Boivin-Masson, Nature 411:948-950, 2001), we identified as nitrogen-fixing legume symbionts at least 50 different strains of Burkholderia caribensis and Ralstonia taiwanensis, all belonging to the beta-subclass of proteobacteria, thus extending the phylogenetic diversity of the rhizobia. R. taiwanensis was found to represent 93% of the Mimosa isolates in Taiwan, indicating that beta-proteobacteria can be the specific symbionts of a legume. The nod genes of rhizobial beta-proteobacteria (beta-rhizobia) are very similar to those of rhizobia from the alpha-subclass (alpha-rhizobia), strongly supporting the hypothesis of the unique origin of common nod genes. The beta-rhizobial nod genes are located on a 0.5-Mb plasmid, together with the nifH gene, in R. taiwanensis and Burkholderia phymatum. Phylogenetic analysis of available nodA gene sequences clustered beta-rhizobial sequences in two nodA lineages intertwined with alpha-rhizobial sequences. On the other hand, the beta-rhizobia were grouped with free-living nitrogen-fixing beta-proteobacteria on the basis of the nifH phylogenetic tree. These findings suggest that beta-rhizobia evolved from diazotrophs through multiple lateral nod gene transfers. (+info)Nodulation of Mimosa spp. by the beta-proteobacterium Ralstonia taiwanensis. (2/48)
Several beta-proteobacteria have been isolated from legume root nodules and some of these are thought to be capable of nodulating and fixing N2. However, in no case has there been detailed studies confirming that they are the active symbionts. Here, Ralstonia taiwanensis LMG19424, which was originally isolated from Mimosa pudica nodules, was transformed to carry the green fluorescent protein (gfp) reporter gene before being used to inoculate axenically-grown seedlings of M. pudica and M. diplotricha. Plants were harvested at various intervals for 56 days after inoculation, then examined for evidence of infection and nodule formation. Nodulation of both Mimosa spp. was abundant, and acetylene reduction assays confirmed that nodules had nitrogenase activity. Confocal laser scanning microscopy (CLSM) showed that fresh M. pudica nodules with nitrogenase activity had infected cells containing bacteroids expressing gfp. In parallel, fixed and embedded nodules from both Mimosa spp. were sectioned for light and electron microscopy, followed by immunogold labeling with antibodies raised against gfp and nitrogenase Fe (nifH) protein. Significant immunolabeling with these antibodies confirmed that R. taiwanensis LMG19424 is an effective N2-fixing symbiont of Mimosa spp. Both species were infected via root hairs and, in all respects, the nodule ontogeny and development was similar to that described for other mimosoid legumes. The nodules were indeterminate with a persistent meristem, an invasion zone containing host cells being invaded via prominent infection threads, and an N2-fixing zone with infected cells containing membrane-bound symbiosomes. (+info)Isolation of Fonsecaea pedrosoi from thorns of Mimosa pudica, a probable natural source of chromoblastomycosis. (3/48)
We report the isolation of Fonsecaea pedrosoi from thorns of the plant Mimosa pudica L. at the place of infection identified by one of our patients. Clinical diagnosis of chromoblastomycosis was established by direct microscopic examination and cultures from the patient's lesion. The same species was isolated from the patient and from the plant. Scanning electron microscopy of the surface of the thorns showed the characteristic conidial arrangement of F. pedrosoi. These data indicate that M. pudica could be a natural source of infection for the fungus F. pedrosoi. (+info)Water channel activities of Mimosa pudica plasma membrane intrinsic proteins are regulated by direct interaction and phosphorylation. (4/48)
cDNAs encoding aquaporins PIP1;1, PIP2;1, and TIP1;1 were isolated from Mimosa pudica (Mp) cDNA library. MpPIP1;1 exhibited no water channel activity; however, it facilitated the water channel activity of MpPIP2;1 in a phosphorylation-dependent manner. Mutagenesis analysis revealed that Ser-131 of MpPIP1;1 was phosphorylated by PKA and that cooperative regulation of the water channel activity of MpPIP2;1 was regulated by phosphorylation of Ser-131 of MpPIP1;1. Immunoprecipitation analysis revealed that MpPIP1;1 binds directly to MpPIP2;1 in a phosphorylation-independent manner, suggesting that phosphorylation of Ser-131 of MpPIP1;1 is involved in regulation of the structure of the channel complex with MpMIP2;1 and thereby affects water channel activity. (+info)Proof that Burkholderia strains form effective symbioses with legumes: a study of novel Mimosa-nodulating strains from South America. (5/48)
Twenty Mimosa-nodulating bacterial strains from Brazil and Venezuela, together with eight reference Mimosa-nodulating rhizobial strains and two other beta-rhizobial strains, were examined by amplified rRNA gene restriction analysis. They fell into 16 patterns and formed a single cluster together with the known beta-rhizobia, Burkholderia caribensis, Burkholderia phymatum, and Burkholderia tuberum. The 16S rRNA gene sequences of 15 of the 20 strains were determined, and all were shown to belong to the genus Burkholderia; four distinct clusters could be discerned, with strains isolated from the same host species usually clustering very closely. Five of the strains (MAP3-5, Br3407, Br3454, Br3461, and Br3469) were selected for further studies of the symbiosis-related genes nodA, the NodD-dependent regulatory consensus sequences (nod box), and nifH. The nodA and nifH sequences were very close to each other and to those of B. phymatum STM815, B. caribensis TJ182, and Cupriavidus taiwanensis LMG19424 but were relatively distant from those of B. tuberum STM678. In addition to nodulating their original hosts, all five strains could also nodulate other Mimosa spp., and all produced nodules on Mimosa pudica that had nitrogenase (acetylene reduction) activities and structures typical of effective N2-fixing symbioses. Finally, both wild-type and green fluorescent protein-expressing transconjugant strains of Br3461 and MAP3-5 produced N2-fixing nodules on their original hosts, Mimosa bimucronata (Br3461) and Mimosa pigra (MAP3-5), and hence this confirms strongly that Burkholderia strains can form effective symbioses with legumes. (+info)Coexistence of Burkholderia, Cupriavidus, and Rhizobium sp. nodule bacteria on two Mimosa spp. in Costa Rica. (6/48)
rRNA gene sequencing and PCR assays indicated that 215 isolates of root nodule bacteria from two Mimosa species at three sites in Costa Rica belonged to the genera Burkholderia, Cupriavidus, and Rhizobium. This is the first report of Cupriavidus sp. nodule symbionts for Mimosa populations within their native geographic range in the neotropics. Burkholderia spp. predominated among samples from Mimosa pigra (86% of isolates), while there was a more even distribution of Cupriavidus, Burkholderia, and Rhizobium spp. on Mimosa pudica (38, 37, and 25% of isolates, respectively). All Cupriavidus and Burkholderia genotypes tested formed root nodules and fixed nitrogen on both M. pigra and M. pudica, and sequencing of rRNA genes in strains reisolated from nodules verified identity with inoculant strains. Inoculation tests further indicated that both Cupriavidus and Burkholderia spp. resulted in significantly higher plant growth and nodule nitrogenase activity (as measured by acetylene reduction assays) relative to plant performance with strains of Rhizobium. Given the prevalence of Burkholderia and Cupriavidus spp. on these Mimosa legumes and the widespread distribution of these plants both within and outside the neotropics, it is likely that both beta-proteobacterial genera are more ubiquitous as root nodule symbionts than previously believed. (+info)Early changes in membrane permeability, production of oxidative burst and modification of PAL activity induced by ergosterol in cotyledons of Mimosa pudica. (7/48)
Ergosterol (a fungal membrane component) was shown to induce transient influx of protons and membrane hyperpolarization in cotyledonary cells of Mimosa pudica L. By contrast, chitosan (a fungal wall component with known elicitor properties) triggered membrane depolarization. In the processes induced by ergosterol, a specific desensitization was observed, since cells did not react to a second ergosterol application but did respond to a chitosan treatment. This comparative study correspondingly shows that ergosterol and chitosan were perceived in a distinct manner by plant cells. Generation of O2*-, visualized by infiltration with nitroblue tetrazolium, was displayed in organs treated with ergosterol and chitosan. This AOS production was preceded by an increase in activity of NADPH oxidase measured in protein extracts of treated cotyledons. In all the previously described processes, cholesterol had no effect, thereby indicating that ergosterol specifically induced these physiological changes known to participate in the reaction chain activated by characteristic elicitors. Contrary to chitosan, ergosterol did not greatly activate secondary metabolism as shown by the small change in content of free phenolics and by the low modification in activity of PAL, the key enzyme of this metabolic pathway. Therefore, future studies have to clarify the signalling cascade triggered by ergosterol recognition. (+info)Energetics of 5-bromo-4-chloro-3-indolyl-alpha-D-mannose binding to the Parkia platycephala seed lectin and its use for MAD phasing. (8/48)
Parkia platycephala belongs to the most primitive group of Leguminosae plants. Its seed lectin is made up of three homologous beta-prism repeats and exhibits binding specificity for mannose/glucose. The properties of the association between the lectin from P. platycephala seeds and monosaccharide ligands were analysed by isothermal titration calorimetry and surface plasmon resonance. The results are consistent with the lectin bearing three thermodynamically identical binding sites for mannose/glucose per monomer with dissociation constants in the millimolar range. Binding of each ligand by the lectin is enthalpically driven. Crystals have been obtained of the lectin in complex with a brominated derivative of mannose (5-bromo-4-chloro-3-indolyl-alpha-D-mannose), which were suitable for deriving an electron-density map by MAD phasing. In agreement with the thermodynamic data, six Br atoms were found in the asymmetric unit of the monoclinic P2(1) crystals, which contained two P. platycephala lectin molecules. The availability of other Br derivatives of monosaccharides (glucose, galactose, fucose) may make this strategy widely useful for structure elucidation of novel lectins or when (as in the case of the P. platycephala lectin) molecular-replacement methods fail. (+info)I am not aware of a widely recognized medical definition for the term "Mimosa." In general, it may refer to a type of plant or a cocktail made with champagne and orange juice. If you are looking for information on a specific medical condition or concept, please provide more context so that I can give you a more accurate and helpful response. Is there something specific you had in mind?
'Cupriavidus' is a genus of bacteria that are gram-negative, motile, and aerobic. They are capable of surviving in various environments, including soil, water, and clinical settings. Some species of this genus were previously classified under the genera 'Ralstonia' and 'Wautersia'. The name 'Cupriavidus' is derived from the Latin word "cuprum," which means copper, reflecting their ability to use copper as an electron acceptor during respiration.
These bacteria are known for their metabolic versatility and can degrade various organic compounds, making them relevant in bioremediation applications. In clinical settings, some species of 'Cupriavidus' have been associated with human infections, particularly in immunocompromised individuals. However, such cases are relatively rare compared to other bacterial pathogens.
It is essential to consult a reliable medical or scientific source for the most up-to-date and accurate information on 'Cupriavidus' species, as research in this field continues to evolve.
A pulvinus is not a term that has a specific medical definition, but it is a term used in anatomy. A pulvinus refers to a small cushion-like structure, usually made up of modified muscle or nerve tissue. It is found in various parts of the body and serves to provide support, protection, or flexibility.
For example, in the eye, there are pulvinar nuclei, which are clusters of neurons located within the thalamus that play a role in visual processing. In botany, a pulvinus is a swelling at the base of a leaf petiole that helps control the movement of the leaf.
Therefore, while "pulvinus" may not have a specific medical definition, it is still a term used in anatomy and physiology to describe certain structures with similar characteristics.
Burkholderia is a genus of gram-negative, rod-shaped bacteria that are widely distributed in the environment, including soil, water, and associated with plants. Some species of Burkholderia are opportunistic pathogens, meaning they can cause infection in individuals with weakened immune systems or underlying medical conditions.
One of the most well-known species of Burkholderia is B. cepacia, which can cause respiratory infections in people with cystic fibrosis and chronic granulomatous disease. Other notable species include B. pseudomallei, the causative agent of melioidosis, a potentially serious infection that primarily affects the respiratory system; and B. mallei, which causes glanders, a rare but severe disease that can affect humans and animals.
Burkholderia species are known for their resistance to many antibiotics, making them difficult to treat in some cases. Proper identification of the specific Burkholderia species involved in an infection is important for determining the most appropriate treatment approach.
Agricultural inoculants are biological products that contain beneficial microorganisms, such as bacteria or fungi, which are applied to seeds, soil, or plant surfaces to enhance plant growth, increase yield, and improve resistance to pests and diseases. These microorganisms form a mutually beneficial relationship with the plants, known as symbiosis, in which they help the plants absorb nutrients from the soil, fix nitrogen, and produce phytohormones that promote root growth and development.
Examples of agricultural inoculants include Rhizobia bacteria, which form nodules on the roots of leguminous plants and convert atmospheric nitrogen into ammonia that can be used by the plant; mycorrhizal fungi, which colonize plant roots and help them absorb water and nutrients from the soil; and Trichoderma fungi, which protect plants from pathogens and promote growth.
Agricultural inoculants are considered an environmentally friendly and sustainable alternative to chemical fertilizers and pesticides, as they improve crop productivity while reducing the negative impacts on the environment and human health.
Radiometric dating is a method used to determine the age of objects, including rocks and other fossilized materials, based on the decay rates of radioactive isotopes. This technique relies on the fact that certain elements, such as carbon-14, potassium-40, and uranium-238, are unstable and gradually decay into different elements over time.
By measuring the ratio of the remaining radioactive isotope to the stable end product, scientists can calculate the age of a sample using the following formula:
age = (ln(Nf/N0)) / λ
where Nf is the number of atoms of the decayed isotope, N0 is the initial number of atoms of the radioactive isotope, and λ is the decay constant.
Radiometric dating has been used to date objects ranging from a few thousand years old to billions of years old, making it an essential tool for archaeologists, geologists, and other scientists who study the history of our planet.
"Ralstonia" is a genus of gram-negative, aerobic bacteria that are commonly found in soil and water. Some species of Ralstonia are known to cause healthcare-associated infections, particularly in patients with compromised immune systems. These infections can include pneumonia, bacteremia, and meningitis. One notable species, Ralstonia solanacearum, is a plant pathogen that causes bacterial wilt in a wide range of plants.
Ralstonia bacteria are known for their ability to form biofilms, which can make them resistant to antibiotics and disinfectants. They can also survive in harsh environments, such as those with low nutrient availability and high salt concentrations. These characteristics make Ralstonia a challenging organism to control in healthcare settings and in the environment.
It's important to note that while Ralstonia bacteria can cause serious infections, they are not typically considered highly virulent or contagious. Instead, infections are often associated with contaminated medical equipment or solutions, such as intravenous fluids, respiratory therapy equipment, and contaminated water sources. Proper infection control practices, including environmental cleaning and disinfection, can help prevent the spread of Ralstonia in healthcare settings.
'Weed control' is not a medical term, but rather it is an agricultural and horticultural term. However, I can provide you with a definition related to those fields:
Weed control refers to the practices and methods used to manage and suppress the growth and spread of unwanted plants (weeds) in crop fields, gardens, lawns, and other landscaped areas. The goal of weed control is to minimize competition between weeds and desirable plants for resources such as water, nutrients, sunlight, and space, thereby improving crop yield, plant health, and aesthetic appeal.
Weed control can be achieved through various cultural, mechanical, biological, and chemical methods, including:
1. Crop rotation: Planting different crops in succession to disrupt the weed life cycle and reduce their populations.
2. Mulching: Applying a layer of organic or inorganic material over the soil surface to prevent weed seed germination and growth.
3. Hand weeding: Physically removing weeds by hand or with tools, either manually or mechanically.
4. Mowing or cutting: Regularly cutting back weeds to prevent them from flowering and producing seeds.
5. Grazing: Allowing animals to feed on weeds in pastures or rangelands.
6. Cover cropping: Planting cover crops to protect the soil, suppress weeds, and improve soil health.
7. Soil solarization: Using clear plastic sheeting to trap heat from the sun and kill weed seeds and roots in the soil.
8. Flaming: Applying heat or flame to weeds to kill them without using chemicals.
9. Herbicides: Applying chemical substances that selectively inhibit or kill weeds while minimizing harm to desirable plants.
It's important to note that proper weed control practices can also help prevent the spread of invasive species and reduce the risk of exposure to harmful plant allergens, toxins, or other health hazards associated with certain types of weeds.