title: Comparison between the short-term and the long-term toxicity of six triazine herbicides on photobacteria Q67.
abstract: The bioluminescence inhibition of six triazine herbicides including desmetryne (DES), simetryn (SIM), velpar (VEL), prometon (PRO), metribuzin (MET), and aminotriazine (AMI) on Vibrio qinghaiensis sp.-Q67 (Q67) was determined to investigate the effects of exposure duration on the ecotoxicological relevance of triazine herbicides. Based on the short-term microplate toxicity analysis (MTA), a long-term MTA was established to assess the impact of exposure time on the toxicities of the herbicides. The results show that the long-term toxicities of DES and SIM are similar to their short-term toxicities, and the long-term toxicities of VEL, PRO, and MET are higher than their short-term toxicities, while AMI without short-term toxicity has a high long-term toxicity. In addition, a parabolic relationship was found between the pEC(50) (the negative logarithm of the EC(50), log 1/EC(50)) and the logarithm of octanol-water partition coefficient (logK(ow)). To better understand their toxicity process, the time-dependent toxicities of the six herbicides on Q67 were determined over a period of 12 h during which measurements were taken every 30 min to generate an integral effect surface related to both concentration and duration.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Life Science, Southwest University, Chongqing 400715, PR China.
authors.forename: Xiang-Wei
authors.initials: XW
authors.lastname: Zhu
authors.forename: Shu-Shen
authors.initials: SS
authors.lastname: Liu
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Ge
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000640:Amitrole / Q000633:toxicity; D004781:Environmental Exposure; D006540:Herbicides / Q000633:toxicity*; D007700:Kinetics; D049449:Luminescence; D010776:Photobacterium / Q000187:drug effects*; D014227:Triazines / Q000633:toxicity*; D014733:Vibrio / Q000187:drug effects*
chemical_list: D006540:Herbicides; D014227:Triazines; C033807:simetryn; C005554:prometone; C009232:semeron; C025641:hexazinone; D000640:Amitrole