title: Interaction of chiral herbicides with soil microorganisms, algae and vascular plants.
abstract: Chiral herbicides are often used in agriculture as racemic mixtures, although studies have shown that the fate and toxicity of herbicide enantiomers to target and non-target plants can be enantioselective and that herbicide toxicity can be mediated by only one enantiomer. If one enantiomer is active against the target plant, the use of enantiomer-rich herbicide mixtures instead of racemic herbicides could decrease the amount of herbicide applied to a crop and the cost of herbicide application, as well as unintended toxic herbicide effects in the environment. Such a change in the management of herbicide applications requires in-depth knowledge and a critical analysis of the fate and effects of herbicide enantiomers in the environment. This review article first synthesizes the current state of knowledge on soil and plant biodegradation of herbicide enantiomers. Second, we discuss our understanding of the biochemical toxicity mechanisms associated with both enantiomers in target and non-target plants gained from state-of-the-art genomic, proteomic and metabolomic tools. Third, we present the emerging view on the "side effects" of herbicides in the root microbiome and their repercussions on target or non-target plant metabolism. Although our review of the literature indicates that the toxicity of herbicide enantiomers is highly variable depending on plant species and herbicides, we found general trends in the enantioselective toxic effects of different herbicides in vascular plants and algae. The present study will be helpful for pesticide risk assessments as well as for the management of applying enriched-enantiomer herbicides.
authors.affiliation: College of Biotechnological and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
authors.forename: Muhammad Asad Ullah
authors.initials: MAU
authors.lastname: Asad
authors.affiliation: Quebec-Ocean and Takuvik Joint International Research Unit, Université Laval, Québec G1VOA6, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Lavoie
authors.affiliation: College of Environment, Zhejiang University of technology, Hangzhou 310032, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Song
authors.affiliation: College of Biotechnological and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
authors.forename: Yujian
authors.initials: Y
authors.lastname: Jin
authors.affiliation: College of Biotechnological and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, PR China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Fu
authors.affiliation: College of Environment, Zhejiang University of technology, Hangzhou 310032, PR China. Electronic address: hfqian@zjut.edu.cn.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qian
mesh_terms: D001673:Biodegradation, Environmental; D006540:Herbicides / Q000737:chemistry*; D058086:Microalgae / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D013237:Stereoisomerism
chemical_list: D006540:Herbicides; D012987:Soil
keywords: Biodegradation; Chiral herbicide; Enantiomer; Enantioselective toxicology; Herbicide toxicity; Plant