title: The metabolic acclimation of Arabidopsis thaliana to arsenate is sensitized by the loss of mitochondrial LIPOAMIDE DEHYDROGENASE2, a key enzyme in oxidative metabolism.
abstract: Mitochondrial lipoamide dehydrogenase is essential for the activity of four mitochondrial enzyme complexes central to oxidative metabolism. The reduction in protein amount and enzyme activity caused by disruption of mitochondrial LIPOAMIDE DEHYDROGENASE2 enhanced the arsenic sensitivity of Arabidopsis thaliana. Both arsenate and arsenite inhibited root elongation, decreased seedling size and increased anthocyanin production more profoundly in knockout mutants than in wild-type seedlings. Arsenate also stimulated lateral root formation in the mutants. The activity of lipoamide dehydrogenase in isolated mitochondria was sensitive to arsenite, but not arsenate, indicating that arsenite could be the mediator of the observed phenotypes. Steady-state metabolite abundances were only mildly affected by mutation of mitochondrial LIPOAMIDE DEHYDROGENASE2. In contrast, arsenate induced the remodelling of metabolite pools associated with oxidative metabolism in wild-type seedlings, an effect that was enhanced in the mutant, especially around the enzyme complexes containing mitochondrial lipoamide dehydrogenase. These results indicate that mitochondrial lipoamide dehydrogenase is an important protein for determining the sensitivity of oxidative metabolism to arsenate in Arabidopsis.
authors: School of Plant Biology, The University of Western Australia, Crawley (Perth), Western Australia, 6009, Australia; Institute of Agriculture, The University of Western Australia, Crawley (Perth), Western Australia, 6009, Australia.
authors: Weihua
authors: W
authors: Chen
authors: Nicolas L
authors: NL
authors: Taylor
authors: Yingjun
authors: Y
authors: Chi
authors: A Harvey
authors: AH
authors: Millar
authors: Hans
authors: H
authors: Lambers
authors: Patrick M
authors: PM
authors: Finnegan
mesh_terms: D000064:Acclimatization / Q000187:drug effects*; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001149:Arsenates / Q000633:toxicity*; D008058:Dihydrolipoamide Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055442:Metabolome / Q000187:drug effects / Q000235:genetics; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D010084:Oxidation-Reduction / Q000187:drug effects; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic / Q000235:genetics; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development
chemical_list: D029681:Arabidopsis Proteins; D001149:Arsenates; D008058:Dihydrolipoamide Dehydrogenase; C000592620:mtLPD1 protein, Arabidopsis; C000592619:mtLPD2 protein, Arabidopsis; C025657:arsenic acid
keywords: 2-oxoglutarate dehydrogenase; glycine decarboxylase; mitochondrial metabolism; pyruvate dehydrogenase; stress response