乙草胺对蛋白核小球藻的毒性效应研究

Toxic Effects of Acetochlor on Chlorella pyrenoidosa

乙草胺是我国使用量最大的除草剂之一,在水体中广泛存在。已有研究证明,乙草胺对人类、老鼠和鱼类具有毒害效应,而关于其对浮游植物影响的研究较少。以蛋白核小球藻(Chlorella pyrenoidosa)为模型,使用1~10000μg·L-1的乙草胺对其进行7 d的暴露实验,考察小球藻生长性能、叶绿素含量、光合作用产氧量以及光合作用相关基因(pbsA、rbcL和rbcS)表达的变化。结果表明,较低浓度的乙草胺可刺激蛋白核小球藻生长,而较高浓度乙草胺则会抑制其生长;并且乙草胺会通过影响小球藻叶绿素的含量而影响光合作用产氧量;小球藻光合作用相关基因pbsA、rbcL和rbcS表达大多显著上升,这可能是对乙草胺胁迫响应的反馈调节。研究表明,乙草胺会对蛋白核小球藻的生长及光合作用产生影响。

Acetochlor is one of the most common herbicides in China and widely distributed in waterbody.Studies have shown that acetochlor has toxic effect on human,mice and fish,but few studies focused on its effects on aquatic plants.In this experiment,Chlorella pyrenoidosa was used as a model organism,and exposed to 1~10000μg·L-1 of acetochlor for 7 days to detect the changes of the growth,chlorophyll content,and photosynthesis oxygen production,as well as expression of photosynthesis-related genes(pbsA,rbcL,and rbcS).These results showed that lower concentration acetochlor stimulated C.pyrenoidosa growth,while higher concentration acetochlor inhibited C.pyrenoidosa growth.The acetochlor could also affect the chlorophyll content and photosynthesis oxygen production of C.pyrenoidosa.The expression of photosynthesis-related genes(pbsA,rbcL and rbcS)in algae was significantly increased under acetochlor exposure in most cases,which may due to the feedback regulation.The present study showed that acetochlor affects the growth and photosynthesis of C.pyrenoidosa.