title: Toxicity assessment of 40 herbicides to the green alga Raphidocelis subcapitata.
abstract: The effects of 40 herbicides with nine modes of action on the green alga Raphidocelis subcapitata were studied by 96-h acute toxicity tests. Results showed that the EC50 of the herbicides with respect to the photosynthetic processes of R. subcapitata ranged from 0.0007 to 4.2286 mgL(-1). Photosynthesis was the process of the green alga most sensitive to the tested herbicides. The most toxic herbicides were atrazine, ametryme, simazine, prometryne, cyanazine, isoproturon, chlorotoluron, diuron, methabenzthiazuron, and paraquat. The EC50 of the protoporphyrinogen oxidase inhibitor oxadiargyl, which was the parameter least sensitive to the herbicides tested in this study, was 42.5 mgL(-1). The descending order of the average acute toxicity to R. subcapitata of herbicides with regard to the nine modes of action was as follows: photosynthetic process>cell division>lipid synthesis, acetyl-coenzyme A carboxylase>acetolactate synthase> 5-enolpyruvyl-shikimate-3-phosphate synthase, glutamine synthase, hormone synthesis>protoporphyrinogen oxidase.
authors.affiliation: Department of Plant Protection, Henan Institute of Science and Technology, Xinxiang, 453003, People's Republic of China. mjyzjhgy@sina.com
authors.forename: Jianyi
authors.initials: J
authors.lastname: Ma
authors.forename: Shufeng
authors.initials: S
authors.lastname: Wang
authors.forename: Pinwei
authors.initials: P
authors.lastname: Wang
authors.forename: Liangjin
authors.initials: L
authors.lastname: Ma
authors.forename: Xiling
authors.initials: X
authors.lastname: Chen
authors.forename: Ruifu
authors.initials: R
authors.lastname: Xu
mesh_terms: D000460:Chlorophyta / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000633:toxicity; D006540:Herbicides / Q000145:classification / Q000633:toxicity*; D010788:Photosynthesis / Q000187:drug effects*; D050768:Protoporphyrinogen Oxidase / Q000037:antagonists & inhibitors; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000145:classification / Q000633:toxicity*
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D014874:Water Pollutants, Chemical; D050768:Protoporphyrinogen Oxidase