Ivantsova Emma, Konig Isaac, Lopez-Scarim Victoria, English Cole, Charnas Savannah R, Souders Christopher L, Martyniuk Christopher J
Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
Department of Chemistry, Federal University of Lavras (UFLA), Minas Gerais, Brazil.
Environ Toxicol Pharmacol. 2023 Mar;98:104084. doi: 10.1016/j.etap.2023.104084. Epub 2023 Feb 23.
Tiafenacil is a newly registered herbicide and a protoporphyrinogen IX oxidase inhibitor. However, sub-lethal effects of PPO-inhibitors in aquatic species are unknown. Embryos or larvae were exposed to 0.1 µg/L up to 10 mg/L tiafenacil for 7-days post-fertilization. Decreased survival (> 50%) and deformities were noted at concentrations > 1 mg/L. Potency (EC) of tiafenacil for 5- and 7-day larvae were 818.1 µg/L and 821.7 µg/L, respectively. Pericardial and yolk sac edema were the most frequent deformities observed. Heartbeat frequency at 3 dpf was decreased in zebrafish exposed to > 10 µg/L tiafenacil, coinciding with increased reactive oxygen species. Oxygen consumption rates were not affected by tiafenacil, nor did we detect differences in indicators of apoptosis. The abundance of eighteen transcripts related to oxidative stress and mitochondrial complexes I through V were unchanged. Larval activity was decreased with exposure to 1000 µg/L tiafenacil. These data contribute to risk assessment for a new class of herbicide.
替芬那西是一种新注册的除草剂，也是一种原卟啉原IX氧化酶抑制剂。然而，PPO抑制剂对水生物种的亚致死效应尚不清楚。在受精后7天内，将胚胎或幼体暴露于浓度为0.1微克/升至10毫克/升的替芬那西中。在浓度大于1毫克/升时，观察到存活率降低（>50%）和畸形。替芬那西对5日龄和7日龄幼体的半数效应浓度（EC）分别为818.1微克/升和821.7微克/升。心包和卵黄囊水肿是观察到的最常见畸形。在暴露于大于10微克/升替芬那西的斑马鱼中，3天胚胎期心跳频率降低，同时活性氧增加。耗氧率不受替芬那西影响，我们也未检测到凋亡指标的差异。与氧化应激以及线粒体复合物I至V相关的18种转录本丰度未发生变化。暴露于1000微克/升替芬那西时，幼体活性降低。这些数据有助于对一类新型除草剂进行风险评估。
