Alachlor is one of the most widely used herbicides and can remain in agricultural soils and wastewater. The toxicity of alachlor to marine life has been rarely studied; therefore, we evaluated the physiological and transcriptional responses in the marine dinoflagellate Prorocentrum minimum. The herbicide led to considerable decreases in P. minimum cell numbers and pigment contents. The EC₅₀ was determined to be 0.373 mg/L. Photosynthesis efficiency and chlorophyll autofluorescence dramatically decreased with increasing alachlor dose and exposure time. Real-time PCR analysis showed that the photosynthesis-related genes PmpsbA, PmatpB, and PmrbcL were induced the most by alachlor; the transcriptional level of each gene varied with time. PmrbcL expression increased after 30 min of alachlor treatment, whereas PmatpB and PmpsbA increased after 24 h. The PmpsbA expression level was highest (5.0 times compared to control) after 6 h of alachlor treatment. There was no significant change in PmpsaA expression with varying treatment time or concentration. Additionally, there was no notable change in the expression of antioxidant genes PmGST and PmKatG, or in ROS accumulation. These suggest that alachlor may affect microalgal photosystem function, with little oxidative stress, causing severe physiological damage to the cells, and even cell death.

甲草胺是使用最广泛的除草剂之一，可保留在农业土壤和废水中。甲草胺对海洋生物的毒性鲜有研究。因此，我们评估了海洋藻鞭毛原中心最低的生理和转录反应。除草剂导致P.最小细胞数和色素含量显着降低。EC ₅₀被确定为0.373 mg / L。随着甲草胺剂量和暴露时间的增加，光合作用效率和叶绿素自发荧光显着下降。实时PCR分析表明，与光合作用相关的基因PmpsbA，PmatpB和PmrbcL被甲草胺诱导最多；每个基因的转录水平随时间变化。甲草胺处理30分钟后PmrbcL表达增加，而24小时后PmatpB和PmpsbA增加。甲草胺处理6小时后，PmpsbA表达水平最高（是对照的5.0倍）。随着治疗时间或浓度的变化，PmpsaA表达无明显变化。此外，抗氧化剂基因PmGST和PmKatG的表达没有明显变化。或ROS积累。这些表明甲草胺可能影响微藻的光系统功能，而氧化应激极小，对细胞造成严重的生理损伤，甚至导致细胞死亡。