title: Strong lethality and teratogenicity of strobilurins on Xenopus tropicalis embryos: Basing on ten agricultural fungicides.
abstract: Agricultural chemical inputs have been considered as a risk factor for the global declines in amphibian populations, yet the application of agricultural fungicides has increased dramatically in recent years. Currently little is known about the potential toxicity of fungicides on the embryos of amphibians. We studied the effects of ten commonly used fungicides (four strobilurins, two SDHIs, two triazoles, fludioxonil and folpet) on Xenopus tropicalis embryos. Lethal and teratogenic effects were respectively examined after 48 h exposure. The median lethal concentrations (LC50s) and the median teratogenic concentrations (TC50s) were determined in line with actual exposure concentrations. These fungicides except two triazoles showed obvious lethal effects on embryos; however LC50s of four strobilurins were the lowest and in the range of 6.81-196.59 μg/L. Strobilurins, SDHIs and fludioxonil induced severe malformations in embryos. Among the ten fungicides, the lowest TC50s were observed for four strobilurins in the range of 0.61-84.13 μg/L. The teratogenicity shared similar dose-effect relationship and consistent phenotypes mainly including microcephaly, hypopigmentation, somite segmentation and narrow fins. The findings indicate that the developmental toxicity of currently-used fungicides involved with ecologic risks on amphibians. Especially strobilurins are highly toxic to amphibian embryos at μg/L level, which is close to environmentally relevant concentrations.
authors.affiliation: Lab of Toxicology, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: Lab of Toxicology, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
authors.forename: Mengyun
authors.initials: M
authors.lastname: Liu
authors.affiliation: Lab of Toxicology, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
authors.forename: Huahong
authors.initials: H
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
authors.forename: Junliang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Lab of Toxicology, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, Shanghai 200241, China. Electronic address: dfhe@des.ecnu.edu.cn.
authors.forename: Defu
authors.initials: D
authors.lastname: He
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D005231:Fatty Acids, Unsaturated / Q000633:toxicity; D005659:Fungicides, Industrial / Q000633:toxicity*; D007928:Lethal Dose 50; D008689:Methacrylates / Q000633:toxicity; D000073739:Strobilurins; D013723:Teratogens / Q000633:toxicity*; D018675:Toxicity Tests; D014230:Triazoles / Q000633:toxicity; D014981:Xenopus / Q000196:embryology*
chemical_list: D005231:Fatty Acids, Unsaturated; D005659:Fungicides, Industrial; D008689:Methacrylates; D000073739:Strobilurins; D013723:Teratogens; D014230:Triazoles; C008556:mucidin
keywords: Embryos; Fungicides; Strobilurins; Teratogenicity; Xenopus tropicalis