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In plants, amino acid catabolism is especially relevant in metabolic stress situations (e.g. limited carbohydrate availability during extended darkness). Under these conditions, amino acids are used as alternative substrates for respiration. Complete oxidation of the branched-chain amino acids
Plants are capable to de novo synthesize the essential amino acids leucine, isoleucine and valine. Studies in recent years, however, also revealed that plants have the potential to degrade leucine or may be all of the branched-chain amino acids. One of the enzymes participating in both biosynthesis
The cucumber mosaic virus (CMV) 2a RNA-dependent RNA polymerase protein has an additional function in Arabidopsis thaliana, which is to stimulate feeding deterrence (antixenosis) against aphids. Antixenosis is thought to increase the probability that aphids, after acquiring CMV particles from brief
Abscisic acid (ABA) is one of the most important phytohormones in plant. PYL proteins were identified to be ABA receptors in Arabidopsis thaliana. Despite the remarkably high degree of sequence similarity, PYL1 and PYL2 exhibit distinct responses toward pyrabactin, an ABA agonist. PYL1 inhibits
Acetohydroxyacid synthase (EC 4.1.3.18; AHAS) catalyzes the initial step in the formation of the branched-chain amino acids. The enzyme from most bacteria is composed of a catalytic subunit, and a smaller regulatory subunit that is required for full activity and for sensitivity to feedback
Acetolactate synthase (ALS), the first enzyme in the biosynthetic pathway of leucine, isoleucine, and valine, is inhibited by imidazolinone herbicides. To understand the molecular basis of imidazolinone resistance, we isolated the ALS gene from an imazapyr-resistant mutant GH90 of Arabidopsis
Acetohydroxyacid synthase (AHAS; EC 4.1.3.18) contains catalytic and regulatory subunits, the latter being required for sensitivity to feedback regulation by leucine, valine and isoleucine. The regulatory subunit of Arabidopsis thaliana AHAS possesses a sequence repeat and we have suggested
Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) catalyses the formation of 2-acetolactate and 2-aceto-2-hydroxybutyrate as the first step in the biosynthesis of the branched-chain amino acids valine, leucine and isoleucine. The enzyme is inhibited by a wide range of substituted sulfonylureas and
A comparison is made of the kinetic characteristics of acetolactate synthase (EC 4.1.3.18) in extracts from Columbia wild type and four near-isogenic, herbicide-resistant mutants of Arabidopsis thaliana (L.) Heynh. The mutants used were the chlorsulfuron-resistant GH50 (csr1-1), the
Cellulose synthases (CESAs) synthesize the β-1,4-glucan chains that coalesce to form cellulose microfibrils in plant cell walls. In addition to a large cytosolic (catalytic) domain, CESAs have eight predicted transmembrane helices (TMHs). However, analogous to the structure of BcsA, a bacterial
The Arabidopsis thaliana accession Shahdara (Sha) differs from Landsberg erecta (Ler) and other accessions in its responses to drought and low water potential including lower levels of proline accumulation. However, Sha maintained greater seedling root elongation at low water potential and a higher
Haberlea rhodopensis is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea's remarkable stress tolerance, the metabolic
Valine, leucine and isoleucine form the small group of branched-chain amino acids (BCAAs) classified by their small branched hydrocarbon residues. Unlike animals, plants are able to de novo synthesize these amino acids from pyruvate, 2-oxobutanoate and acetyl-CoA. In plants, biosynthesis follows the
Fatty alcohols play a variety of biological roles in all kingdoms of life. Fatty acyl reductase (FAR) enzymes catalyze the reduction of fatty acyl-coenzyme A (CoA) or fatty acyl-acyl carrier protein substrates to primary fatty alcohols. FAR enzymes have distinct substrate specificities with regard
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Whereas proline accumulates through de novo biosynthesis in plants subjected to osmotic stress, leucine, isoleucine, and valine accumulation in drought-stressed Arabidopsis thaliana is caused by abscisic acid-regulated protein degradation. In response to several kinds of abiotic stress,