The immediate physical zone surrounding plant roots that include the plant roots. It is an area of intense and complex biological activity involving plants, microorganisms, other soil organisms, and the soil.

The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.

The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)

A species of nonpathogenic fluorescent bacteria found in feces, sewage, soil, and water, and which liquefy gelatin.

A trinitrobenzene derivative with antispasmodic properties that is used primarily as a laboratory reagent.

The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

A plant genus of the family FABACEAE that is a source of prosopis gum.

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.

A natural association between organisms that is detrimental to at least one of them. This often refers to the production of chemicals by one microorganism that is harmful to another.

One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.

The relationships of groups of organisms as reflected by their genetic makeup.

A plant family of the order Rhizophorales, subclass Rosidae, class Magnoliopsida, that includes mangrove trees.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

Phenazines are nitrogen-containing heterocyclic compounds that have been widely studied for their antibacterial, antifungal, and antiparasitic properties, and can be found in various natural sources such as bacteria and fungi, or synthesized chemically.

Use of naturally-occuring or genetically-engineered organisms to reduce or eliminate populations of pests.

A genus of destructive root-parasitic OOMYCETES in the family Pythiaceae, order Peronosporales, commonly found in cultivated soils all over the world. Differentiation of zoospores takes place in a vesicle.

A species of gram-negative, aerobic bacteria isolated from soil and water as well as clinical specimens. Occasionally it is an opportunistic pathogen.

A genus of gram-negative, aerobic, rod-shaped bacteria widely distributed in nature. Some species are pathogenic for humans, animals, and plants.

A plant genus of the family POACEAE that is the source of EDIBLE GRAIN. A hybrid with rye (SECALE CEREALE) is called TRITICALE. The seed is ground into FLOUR and used to make BREAD, and is the source of WHEAT GERM AGGLUTININS.

Cultivated plants or agricultural produce such as grain, vegetables, or fruit. (From American Heritage Dictionary, 1982)

A type of viscous polysaccharide that is secreted from PLANTS. It has natural properties that are useful in the formulation of ADHESIVES.

Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.

A plant genus of the family SALICACEAE. Members contain salicin, which yields SALICYLIC ACID.

Substances released by PLANTS such as PLANT GUMS and PLANT RESINS.

A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.

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.

A species of the Beta genus. Cultivars are used as a source of beets (root) or chard (leaves).

The variety of all native living organisms and their various forms and interrelationships.

Diseases of plants.

A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)

A plant genus of the family FABACEAE known for the edible beans.

A plant species of the family FABACEAE widely cultivated for ANIMAL FEED.

The goosefoot plant family of the order Caryophyllales, subclass Caryophyllidae, class Magnoliopsida. It includes beets and chard (BETA VULGARIS), as well as SPINACH, and salt tolerant plants.

A physiologically diverse phylum of acidophilic, gram-negative bacteria found in a wide variety of habitats, but particularly abundant in soils and sediments.

A creeping annual plant species of the CUCURBITACEAE family. It has a rough succulent, trailing stem and hairy leaves with three to five pointed lobes.

A plant genus in the CHENOPODIACEAE family.

Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.

A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.

Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.

A group of different species of microorganisms that act together as a community.

The spectrum of different living organisms inhabiting a particular region, habitat, or biotope.

Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.

The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.

A plant genus of the family FABACEAE.

A phylum of bacteria consisting of the purple bacteria and their relatives which form a branch of the eubacterial tree. This group of predominantly gram-negative bacteria is classified based on homology of equivalent nucleotide sequences of 16S ribosomal RNA or by hybridization of ribosomal RNA or DNA with 16S and 23S ribosomal RNA.

Electrophoresis in which various denaturant gradients are used to induce nucleic acids to melt at various stages resulting in separation of molecules based on small sequence differences including SNPs. The denaturants used include heat, formamide, and urea.

A genus of GRAM-POSITIVE ENDOSPORE-FORMING RODS in the family Paenibacillaceae.

Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)

A large plant family in the order Apiales, also known as Umbelliferae. Most are aromatic herbs with alternate, feather-divided leaves that are sheathed at the base. The flowers often form a conspicuous flat-topped umbel. Each small individual flower is usually bisexual, with five sepals, five petals, and an enlarged disk at the base of the style. The fruits are ridged and are composed of two parts that split open at maturity.

A plant genus of the family POACEAE. The EDIBLE GRAIN, barley, is widely used as food.

A mitosporic fungal genus commonly isolated from soil. Some species are the cause of wilt diseases in many different plants.

A plant genus of the family POACEAE widely cultivated in the tropics for the sweet cane that is processed into sugar.

A plant growing in a location where it is not wanted, often competing with cultivated plants.

A plant species of the family SOLANACEAE, native of South America, widely cultivated for their edible, fleshy, usually red fruit.

A species of gram-negative, aerobic bacteria that is found in soil and which causes formation of root nodules on some, but not all, types of field pea, lentil, kidney bean, and clover.

Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.

A genus of gram-negative aerobic bacteria that occurs free-living in the soil or associated with the roots of cereal crops or grasses (POACEAE).

A genus of gram-negative, aerobic, rod-shaped bacteria. Organisms in this genus had originally been classified as members of the PSEUDOMONAS genus but overwhelming biochemical and chemical findings indicated the need to separate them from other Pseudomonas species, and hence, this new genus was created.

A plant genus of the family BRASSICACEAE known for the root used in hot SPICES. It is also the source of HORSERADISH PEROXIDASE which is widely used in laboratories.

The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.

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.

A plant family of the order Myrtales, subclass Rosidae, class Magnoliopsida. They are mostly trees and shrubs growing in warm areas.

The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.

Class of BACTERIA with diverse morphological properties. Strains of Actinobacteria show greater than 80% 16S rDNA/rRNA sequence similarity among each other and also the presence of certain signature nucleotides. (Stackebrandt E. et al, Int. J. Syst. Bacteriol. (1997) 47:479-491)

A plant species of the genus CHRYSANTHEMUM, family ASTERACEAE. The flowers contain PYRETHRINS, cinerolones, and chrysanthemines which are powerful contact insecticides. Most in the old Pyrethrum genus are reclassified to TANACETUM; some to other ASTERACEAE genera.

A technique for growing plants in culture solutions rather than in soil. The roots are immersed in an aerated solution containing the correct proportions of essential mineral salts. (From Concise Dictionary of Biology, 1990)

A family of gram-negative bacteria which are saprophytes, symbionts, or plant pathogens.

Any of the various plants of the genus Lactuca, especially L. sativa, cultivated for its edible leaves. (From American Heritage Dictionary, 2d ed)

A genus of gram-negative, aerobic, rod-shaped bacteria that activate PLANT ROOT NODULATION in leguminous plants. Members of this genus are nitrogen-fixing and common soil inhabitants.

Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)

The routing of water to open or closed areas where it is used for agricultural purposes.

Substances or mixtures that are added to the soil to supply nutrients or to make available nutrients already present in the soil, in order to increase plant growth and productivity.

A plant genus of the family CUPRESSACEAE. Cypress ordinarily refers to this but also forms part of the name of plants in other genera.

A genus of straight or slightly curved gram-negative rods occurring singly or in pairs and isolated from sludge, mud, and river and pond water. (From Bergey's Manual of Determinative Bacteriology, 9th ed)

A plant genus of the family CYPERACEAE. SESQUITERPENES are found in some of the species.

New immature growth of a plant including stem, leaves, tips of branches, and SEEDLINGS.

Proteins found in any species of bacterium.

A family of gram-negative bacteria usually found in soil or water and including many plant pathogens and a few animal pathogens.

The broom-rape plant family of the order Lamiales.

Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.

Annual cereal grass of the family POACEAE and its edible starchy grain, rice, which is the staple food of roughly one-half of the world's population.

Organisms, biological agents, or biologically-derived agents used strategically for their positive or adverse effect on the physiology and/or reproductive health of other organisms.

A variable annual leguminous vine (Pisum sativum) that is cultivated for its rounded smooth or wrinkled edible protein-rich seeds, the seed of the pea, and the immature pods with their included seeds. (From Webster's New Collegiate Dictionary, 1973)

A plant genus of the family SALICACEAE. Balm of Gilead is a common name used for P. candicans, or P. gileadensis, or P. jackii, and sometimes also used for ABIES BALSAMEA or for COMMIPHORA.

Symbiotic combination (dual organism) of the MYCELIUM of FUNGI with the roots of plants (PLANT ROOTS). The roots of almost all higher plants exhibit this mutually beneficial relationship, whereby the fungus supplies water and mineral salts to the plant, and the plant supplies CARBOHYDRATES to the fungus. There are two major types of mycorrhizae: ectomycorrhizae and endomycorrhizae.

A plant genus of the family POACEAE that contains the Poa p Ia allergen and allergen C KBGP.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in water, sewage, soil, meat, hospital environments, and on the skin and in the intestinal tract of man and animals as a commensal.

Enzymes that catalyze the cleavage of a carbon-carbon bond by means other than hydrolysis or oxidation. This subclass contains the DECARBOXYLASES, the ALDEHYDE-LYASES, and the OXO-ACID-LYASES. EC 4.1.

Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.

A plant species of the genus SOLANUM, family SOLANACEAE. The starchy roots are used as food. SOLANINE is found in green parts.

An order of gram-positive, primarily aerobic BACTERIA that tend to form branching filaments.

An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.

Very young plant after GERMINATION of SEEDS.