The capacity of an organism to defend itself against pathological processes or the agents of those processes. This most often involves innate immunity whereby the organism responds to pathogens in a generic way. The term disease resistance is used most frequently when referring to plants.

Diseases of plants.

A compound obtained from the bark of the white willow and wintergreen leaves. It has bacteriostatic, fungicidal, and keratolytic actions.

The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.

Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.

The functional hereditary units of PLANTS.

A species of gram-negative, fluorescent, phytopathogenic bacteria in the genus PSEUDOMONAS. It is differentiated into approximately 50 pathovars with different plant pathogenicities and host specificities.

PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.

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.

Eukaryotes in the group STRAMENOPILES, formerly considered FUNGI, whose exact taxonomic level is unsettled. Many consider Oomycetes (Oomycota) a phylum in the kingdom Stramenopila, or alternatively, as Pseudofungi in the phylum Heterokonta of the kingdom Chromista. They are morphologically similar to fungi but have no close phylogenetic relationship to them. Oomycetes are found in both fresh and salt water as well as in terrestrial environments. (Alexopoulos et al., Introductory Mycology, 4th ed, pp683-4). They produce flagellated, actively motile spores (zoospores) that are pathogenic to many crop plants and FISHES.

The inherent or induced capacity of plants to withstand or ward off biological attack by pathogens.

Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.

Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.

A genus of OOMYCETES in the family Peronosporaceae. Most species are obligatory parasites and many are plant pathogens.

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.

The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

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.

A genus of FUNGI, in the family Magnaporthaceae of uncertain position (incertae sedis). It is best known for its species, M. grisea, which is one of the most popular experimental organisms of all fungal plant pathogens. Its anamorph is PYRICULARIA GRISEA.

Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)

A mitosporic Loculoascomycetes fungal genus including some economically important plant parasites. Teleomorphs include Mycosphaerella and Venturia.

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

A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.

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.

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

Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.

A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.

A genus of destructive parasitic OOMYCETES in the family Peronosporaceae, order Peronosporales, affecting numerous fruit, vegetable, and other crops. Differentiation of zoospores usually takes place in the sporangium and no vesicle is formed. It was previously considered a fungus.

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

Deoxyribonucleic acid that makes up the genetic material of plants.

A genus in the family XANTHOMONADACEAE whose cells produce a yellow pigment (Gr. xanthos - yellow). It is pathogenic to plants.

Eighteen-carbon cyclopentyl polyunsaturated fatty acids derived from ALPHA-LINOLENIC ACID via an oxidative pathway analogous to the EICOSANOIDS in animals. Biosynthesis is inhibited by SALICYLATES. A key member, jasmonic acid of PLANTS, plays a similar role to ARACHIDONIC ACID in animals.

Simultaneous resistance to several structurally and functionally distinct drugs.

A group of alicyclic hydrocarbons with the general formula R-C5H9.

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

A mitosporic Leotiales fungal genus of plant pathogens. It has teleomorphs in the genus Botryotina.

The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

A phylum of fungi that produce their sexual spores (basidiospores) on the outside of the basidium. It includes forms commonly known as mushrooms, boletes, puffballs, earthstars, stinkhorns, bird's-nest fungi, jelly fungi, bracket or shelf fungi, and rust and smut fungi.

The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.

The ability of bacteria to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).

A plant genus of the family SOLANACEAE. Members contain SOLANACEOUS ALKALOIDS. Some species in this genus are called deadly nightshade which is also a common name for ATROPA BELLADONNA.

Genetic loci associated with a QUANTITATIVE TRAIT.

A plant genus of the family SOLANACEAE. The hot peppers yield CAPSAICIN, which activates VANILLOID RECEPTORS. Several varieties have sweet or pungent edible fruits that are used as vegetables when fresh and spices when the pods are dried.

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

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

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A species of parasitic OOMYCETES in the family Peronosporaceae that is the causative agent of late blight of potato.

A mitosporic Hypocreales fungal genus, various species of which are important parasitic pathogens of plants and a variety of vertebrates. Teleomorphs include GIBBERELLA.

Substances that reduce the growth or reproduction of BACTERIA.

The interactions between a host and a pathogen, usually resulting in disease.

Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.

Any method used for determining the location of and relative distances between genes on a chromosome.

A group of compounds which can be described as benzo-pyrano-furano-benzenes which can be formed from ISOFLAVONES by internal coupling of the B ring to the 4-ketone position. Members include medicarpin, phaseolin, and pisatin which are found in FABACEAE.

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

Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).

The use of DNA recombination (RECOMBINATION, GENETIC) to prepare a large gene library of novel, chimeric genes from a population of randomly fragmented DNA from related gene sequences.

A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)

Infections or infestations with parasitic organisms. The infestation may be experimental or veterinary.

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

Derivatives of ethylene, a simple organic gas of biological origin with many industrial and biological use.

The genetic complement of a plant (PLANTS) as represented in its DNA.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

Diseases of freshwater, marine, hatchery or aquarium fish. This term includes diseases of both teleosts (true fish) and elasmobranchs (sharks, rays and skates).

An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.

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.

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

Proteins found in any species of bacterium.

A genus of mitosporic Phyllachoraceae fungi which contains at least 40 species of plant parasites. They have teleomorphs in the genus Glomerella (see PHYLLACHORALES).

A mitosporic Loculoascomycetes fungal genus including several plant pathogens and at least one species which produces a highly phytotoxic antibiotic. Its teleomorph is Lewia.

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.

The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

A plant genus in the family FABACEAE which is the source of edible beans and the lectin PHYTOHEMAGGLUTININS.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

Genotypic differences observed among individuals in a population.

A plant family of the order Solanales, subclass Asteridae. Among the most important are POTATOES; TOMATOES; CAPSICUM (green and red peppers); TOBACCO; and BELLADONNA.

Nonsusceptibility of bacteria to the action of TETRACYCLINE which inhibits aminoacyl-tRNA binding to the 30S ribosomal subunit during protein synthesis.

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.

The type species of TOBAMOVIRUS which causes mosaic disease of tobacco. Transmission occurs by mechanical inoculation.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.

A mitosporic Ceratobasidiaceae fungal genus that is an important plant pathogen affecting potatoes and other plants. There are numerous teleomorphs.

The largest genus in the family Myxobolidae, class MYXOSPOREA, containing over 400 species.

Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.

The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.

A plant genus of the family APIACEAE used for flavoring food.

Plants or plant parts which are harmful to man or other animals.

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

The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.

Nonsusceptibility of an organism to the action of penicillins.

A genus of plant viruses in the family FLEXIVIRIDAE, that cause mosaic and ringspot symptoms. Transmission occurs mechanically. Potato virus X is the type species.

The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.

A species of gram-negative bacteria in the genus XANTHOMONAS, which causes citrus cankers and black rot in plants.

A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.

Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.

Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.

Potent cholinesterase inhibitor used as an insecticide and acaricide.

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

The ability of fungi to resist or to become tolerant to chemotherapeutic agents, antifungal agents, or antibiotics. This resistance may be acquired through gene mutation.

A mitosporic fungal genus including both saprophytes and plant parasites.

A species of gram-negative, aerobic bacteria that is pathogenic for plants.

Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.

A genus of RNA plant viruses in the family FLEXIVIRIDAE, containing slightly flexuous filaments, often transmitted by aphids in a non-persistent manner. Carnation latent virus is the type species.

The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.

Plant growth factor derived from the root of Scopolia carniolica or Scopolia japonica.

The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.

A plant genus of the family FABACEAE that is a source of SPARTEINE, lupanine and other lupin alkaloids.

Interruption or suppression of the expression of a gene at transcriptional or translational levels.

A plant genus of the family MALVACEAE. It is the source of COTTON FIBER; COTTONSEED OIL, which is used for cooking, and GOSSYPOL. The economically important cotton crop is a major user of agricultural PESTICIDES.

A plant genus of the family LINACEAE that is cultivated for its fiber (manufactured into linen cloth). It contains a trypsin inhibitor and the seed is the source of LINSEED OIL.

Very young plant after GERMINATION of SEEDS.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

DNA sequences that form the coding region for a trans-activator protein that specifies rapid growth in human immunodeficiency virus (HIV). vpr is short for viral protein R, where R is undefined.

Infections with bacteria of the family FLAVOBACTERIACEAE.

The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

Transport proteins that carry specific substances in the blood or across cell membranes.

Nonsusceptibility of bacteria to the action of the beta-lactam antibiotics. Mechanisms responsible for beta-lactam resistance may be degradation of antibiotics by BETA-LACTAMASES, failure of antibiotics to penetrate, or low-affinity binding of antibiotics to targets.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that causes rotting, particularly of storage tissues, of a wide variety of plants and causes a vascular disease in CARROTS; and POTATO plants.

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 type of strength-building exercise program that requires the body muscle to exert a force against some form of resistance, such as weight, stretch bands, water, or immovable objects. Resistance exercise is a combination of static and dynamic contractions involving shortening and lengthening of skeletal muscles.

An enzyme that catalyzes the deamination of PHENYLALANINE to form trans-cinnamate and ammonia.

A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

A plant genus in the family VITACEAE, order Rhamnales, subclass Rosidae. It is a woody vine cultivated worldwide. It is best known for grapes, the edible fruit and used to make WINE and raisins.

Infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure.

Any of the hormones produced naturally in plants and active in controlling growth and other functions. There are three primary classes: auxins, cytokinins, and gibberellins.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that may be pathogenic for frogs, fish, and mammals, including man. In humans, cellulitis and diarrhea can result from infection with this organism.

Common name of the order Siluriformes. This order contains many families and over 2,000 species, including venomous species. Heteropneustes and Plotosus genera have dangerous stings and are aggressive. Most species are passive stingers.

Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.

An order of insects, restricted mostly to the tropics, containing at least eight families. A few species occur in temperate regions of North America.

A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.

Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.

The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

Elements of limited time intervals, contributing to particular results or situations.

Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.

A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.

The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.

The mating of plants or non-human animals which are closely related genetically.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.

The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.

An order of fungi in the phylum ASCOMYCOTA that includes a number of species which are parasitic on higher plants, insects, or fungi. Other species are saprotrophic.

Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.

Screening techniques first developed in yeast to identify genes encoding interacting proteins. Variations are used to evaluate interplay between proteins and other molecules. Two-hybrid techniques refer to analysis for protein-protein interactions, one-hybrid for DNA-protein interactions, three-hybrid interactions for RNA-protein interactions or ligand-based interactions. Reverse n-hybrid techniques refer to analysis for mutations or other small molecules that dissociate known interactions.

A plant genus in the family ROSACEAE, order Rosales, subclass Rosidae. It is best known as a source of the edible fruit (apple) and is cultivated in temperate climates worldwide.

A 170-kDa transmembrane glycoprotein from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS. It serves as an ATP-dependent efflux pump for a variety of chemicals, including many ANTINEOPLASTIC AGENTS. Overexpression of this glycoprotein is associated with multidrug resistance (see DRUG RESISTANCE, MULTIPLE).

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.

Nonsusceptibility of a microbe to the action of ampicillin, a penicillin derivative that interferes with cell wall synthesis.

A constitution or condition of the body which makes the tissues react in special ways to certain extrinsic stimuli and thus tends to make the individual more than usually susceptible to certain diseases.

Nonsusceptibility of bacteria to the action of CHLORAMPHENICOL, a potent inhibitor of protein synthesis in the 50S ribosomal subunit where amino acids are added to nascent bacterial polypeptides.

A species of gram-negative, aerobic bacteria isolated from soil and the stems, leafs, and roots of plants. Some biotypes are pathogenic and cause the formation of PLANT TUMORS in a wide variety of higher plants. The species is a major research tool in biotechnology.

The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.

Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.

The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.

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.

A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

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

A plant genus of the family POACEAE. The grain is used for FOOD and for ANIMAL FEED. This should not be confused with KAFFIR LIME or with KEFIR milk product.

The gourd plant family of the order Violales, subclass Dilleniidae, class Magnoliopsida. It is sometimes placed in its own order, Cucurbitales. 'Melon' generally refers to CUCUMIS; CITRULLUS; or MOMORDICA.

A plant species of the family POACEAE that is widely cultivated for its edible seeds.

DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.

Polysaccharides composed of repeating glucose units. They can consist of branched or unbranched chains in any linkages.

A naphthacene antibiotic that inhibits AMINO ACYL TRNA binding during protein synthesis.

Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)

Prolonged dry periods in natural climate cycle. They are slow-onset phenomena caused by rainfall deficit combined with other predisposing factors.

The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.

RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.

Viruses parasitic on plants higher than bacteria.

Infections with bacteria of the genus SERRATIA.

A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.

Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.

A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.

The functional hereditary units of BACTERIA.

A large increase in oxygen uptake by neutrophils and most types of tissue macrophages through activation of an NADPH-cytochrome b-dependent oxidase that reduces oxygen to a superoxide. Individuals with an inherited defect in which the oxidase that reduces oxygen to superoxide is decreased or absent (GRANULOMATOUS DISEASE, CHRONIC) often die as a result of recurrent bacterial infections.

Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.

The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.

A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.

Non-susceptibility of a microbe to the action of METHICILLIN, a semi-synthetic penicillin derivative.

A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in soil, water, food, and clinical specimens. It is a prominent opportunistic pathogen for hospitalized patients.

Proteins found in any species of fungus.

A commercially important species of SALMON in the family SALMONIDAE, order SALMONIFORMES, which occurs in the North Atlantic.

Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.

A sequential pattern of amino acids occurring more than once in the same protein sequence.

A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).

A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).

The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.

Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.

Non-susceptibility of an organism to the action of the cephalosporins.

The systematic study of the complete DNA sequences (GENOME) of organisms.

A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.