title: Analyzing Arabidopsis thaliana root proteome provides insights into the molecular bases of enantioselective imazethapyr toxicity.
abstract: Imazethapyr (IM) is a widely used chiral herbicide that inhibits the synthesis of branched-chain amino acids (BCAAs). IM is thought to exert its toxic effects on amino acid synthesis mainly through inhibition of acetolactate synthase activity, but little is known about the potential effects of IM on other key biochemical pathways. Here, we exposed the model plant Arabidospsis thaliana to trace S- and R-IM enantiomer concentrations and examined IM toxicity effects on the root proteome using iTRAQ. Conventional analyses of root carbohydrates, organic acids, and enzyme activities were also performed. We discovered several previously unknown key biochemical pathways targeted by IM in Arabidospsis. 1,322 and 987 proteins were differentially expressed in response to R- and S-IM treatments, respectively. Bioinformatics and physiological analyses suggested that IM reduced the BCAA tissue content not only by strongly suppressing BCAA synthesis but also by increasing BCAA catabolism. IM also affected sugar and starch metabolism, changed the composition of root cell walls, increased citrate production and exudation, and affected the microbial community structure of the rhizosphere. The present study shed new light on the multiple toxicity mechanisms of a selective herbicide on a model plant.
authors.affiliation: 1] Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310032, P. R. of China [2] College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qian
authors.affiliation: College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, P. R. of China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Lu
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Ding
authors.affiliation: Quebec-Ocean and Takuvik Joint International Research Unit, Université Laval, Québec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Lavoie
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, P. R. of China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, P. R. of China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Fu
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects / Q000235:genetics; D050260:Carbohydrate Metabolism / Q000187:drug effects; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002952:Citric Acid Cycle / Q000187:drug effects; D006540:Herbicides / Q000633:toxicity*; D009539:Nicotinic Acids / Q000633:toxicity*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D020543:Proteome / Q000032:analysis / Q000187:drug effects*; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D017423:Sequence Analysis, RNA; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry; D014574:Uronic Acids / Q000378:metabolism
chemical_list: D000596:Amino Acids; D006540:Herbicides; D009539:Nicotinic Acids; D020543:Proteome; D012336:RNA, Ribosomal, 16S; D014574:Uronic Acids; C093630:imazethapyr