乙草胺胁迫对水华微囊藻光合生理特性的影响  

Effects of Acetochlor Stress on Photosynthetic Physiology of Microcystis flos-aquae

作　　者：李俊杰 李玲[1] 黄沛玲 Li Junjie;Li Ling;Huang Peiling(College of Chemical Engineering,Huaqiao University,Xiamen 361021,China)

机构地区：[1]华侨大学化工学院,厦门361021

出　　处：《生态毒理学报》2020年第5期244-254,共11页Asian Journal of Ecotoxicology

基　　金：福建省中青年教师科研项目(JAT160027);石狮市科技计划项目(2016FS21);华侨大学研究生科研创新能力培育计划资助项目(12BS108)。

摘　　要：除草剂乙草胺(ACT)施用后会通过灌溉侵蚀或地表径流等方式进入水环境造成污染。为探究ACT对浮游植物的影响,选择水华微囊藻作为受试生物,测定叶绿素a(Chl a)含量、叶绿素荧光参数、藻蛋白和藻胆蛋白相对含量的变化,观察藻细胞超微结构的变化,综合评估ACT对浮游植物光合作用的影响。结果表明,当ACT浓度≥0.1 mg·L-1时,Chl a含量开始显著降低(P<0.05);在低浓度(0.01~1 mg·L-1)ACT胁迫下,水华微囊藻能够通过自身调节,使得最大光合效率(F v/F m)、PSⅡ的实际光合效率(Y(Ⅱ))和快速光响应曲线不受ACT影响;而在高浓度(10~50 mg·L-1)处理组中,F v/F m、Y(Ⅱ)、快速光响应曲线、光响应曲线的初始斜率(α)和最大潜在相对电子传递速率(ETR max)均显著降低(P<0.05);别藻蓝蛋白(APC)、藻蓝蛋白(PC)和藻红蛋白(PE)的相对含量分别在ACT浓度为1、10和10 mg·L-1时开始显著降低(P<0.05)。这些结果说明,在高浓度ACT胁迫下,水华微囊藻的叶绿素合成受阻,光合色素减少,捕光能力、光能转化效率及相对电子传递速率均下降,光合活性降低,且ACT对藻胆蛋白的抑制作用顺序为别藻蓝蛋白>藻蓝蛋白>藻红蛋白,而半饱和光强(I k)显著增加(P<0.05),耐受能力增强,从而使光合作用受到抑制。透射电子显微镜结果表明,藻细胞结构会被ACT破坏,细胞变形且出现质壁分离,类囊体损伤且垂直于细胞壁,气泡、藻青素小粒和糖原减少,脂质颗粒增多,细胞内部紊乱,捕光色素减少,导致光合作用受阻。上述研究结果为全面评价ACT环境风险及农药的合理利用提供科学依据。Because of extensive use,the herbicide acetochlor(ACT)has become a serious environmental pollutants by irrigation erosion or surface runoff,and the aquatic environment in our country has been severely polluted.In order to study the influences of ACT on phytoplankton,Microcystis flos-aquae was used as the model organism,and the changes of chlorophyll a content,chlorophyll fluorescence parameters,relative content of algal protein and phycobiliprotein,and the ultrastructure of algal cells before and after exposure to ACT were investigated,respectively.The results showed that the contents of Chl a significantly decreased when the concentrations of ACT were higher than 0.1 mg·L-1.The maximum photosynthetic efficiency(F v/F m),the actual photosynthetic efficiency of PSⅡ(Y(Ⅱ)),and Rapid Light Curve of Microcystis flos-aquae were not affected through self-regulation under the stress of lower concentrations(0.01~1 mg·L-1)of ACT,but these parameters as well as the initial slope of the light response curve(α),and maximum potential relative electron transfer rate(ETR max)were all significantly reduced(P<0.05)under the higher concentrations(10~50 mg·L-1)of ACT.The relative content of allophycocyanin(APC),phycocyanin(PC),phycoerythrin(PE),and phycoprotein significantly decreased in groups with ACT concentrations of 1,10 and 10 mg·L-1,respectively.The results indicated that chlorophyll synthesis of Microcystis flos-aquae was blocked under higher concentrations of ACT stress.The photosynthetic pigments,light-capturing capacity,light energy conversion efficiency,relative electron transfer rate,and photosynthetic activity were all reduced.The inhibition order of ACT on phycobiliproteins was allophycocyanin>phycocyanin>phycoerythrin.In addition,the semi-saturated light intensity(I k)increased significantly(P<0.05),and the tolerance was enhanced,which demonstrated that photosynthesis was supressed.Transmission electron microscopy results showed that the cells were deformed,evident plasmolysis was observed,the thylakoids wer

关 键 词：乙草胺 水华微囊藻 光合作用 叶绿素荧光参数 

分 类 号：X171.5[环境科学与工程—环境科学]