Herbicide Resistance: Diminished or failed response of PLANTS to HERBICIDES.Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Plant Weeds: A plant growing in a location where it is not wanted, often competing with cultivated plants.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.Acetolactate Synthase: A flavoprotein enzyme that catalyzes the formation of acetolactate from 2 moles of PYRUVATE in the biosynthesis of VALINE and the formation of acetohydroxybutyrate from pyruvate and alpha-ketobutyrate in the biosynthesis of ISOLEUCINE. This enzyme was formerly listed as EC A plant genus of the family POACEAE that is grown mainly as a hay crop.Aminobutyrates: Derivatives of BUTYRIC ACID that contain one or more amino groups attached to the aliphatic structure. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the aminobutryrate structure.Drug Resistance: 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.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Acetyl-CoA Carboxylase: A carboxylating enzyme that catalyzes the conversion of ATP, acetyl-CoA, and HCO3- to ADP, orthophosphate, and malonyl-CoA. It is a biotinyl-protein that also catalyzes transcarboxylation. The plant enzyme also carboxylates propanoyl-CoA and butanoyl-CoA (From Enzyme Nomenclature, 1992) EC 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.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Tobacco: A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.Atrazine: A selective triazine herbicide. Inhalation hazard is low and there are no apparent skin manifestations or other toxicity in humans. Acutely poisoned sheep and cattle may show muscular spasms, fasciculations, stiff gait, increased respiratory rates, adrenal degeneration, and congestion of the lungs, liver, and kidneys. (From The Merck Index, 11th ed)Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.2,4-Dichlorophenoxyacetic Acid: An herbicide with irritant effects on the eye and the gastrointestinal system.Mutation: 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.Drug Resistance, Microbial: 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).Drug Resistance, Bacterial: 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).2-Methyl-4-chlorophenoxyacetic Acid: A powerful herbicide used as a selective weed killer.Drug Resistance, Neoplasm: Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.