摘要
为探究农药和重金属对拟柱孢藻(Cylindrospermopsis raciborskii)的联合毒性效应,本试验研究了草甘膦和铅单一及联合暴露对其生长、叶绿素含量、光合系统和抗氧化酶的影响.结果表明:和对照相比,拟柱孢藻的生长率在低浓度草甘膦(0.7 mg·L^(-1))和铅(0.1和10 mg·L^(-1))单一暴露时显著升高,而在高浓度草甘膦(17.1 mg·L^(-1))暴露时明显降低.同时,草甘膦和铅联合暴露与单一暴露相比生长率也显著下降,表明联合暴露后对拟柱胞藻毒性增强.联合暴露后荧光诱导曲线初始斜率(M0)、相对可变荧光(VJ)、单位反应中心天线色素吸收的光能(ABS/RC)、反应中心的热耗散能量(DI0/RC)、用于还原QA的能量(TR0/RC)和能量耗散量子比率(φD0)和草甘膦或铅单一暴露相比均显著升高;以吸收光能为基础的性能指数(PIABS)、PSII潜在活性(FV/F0)、最大光化学效率φP0、t=0时传递链中超过QA的其他电子受体的概率ψ0和用于热耗散的量子比率φ_(E0)则显著降低,说明联合暴露能减少有活性的光合反应中心,减缓电子传递速率,造成QA-大量累积.低浓度的草甘膦和铅单一暴露后和对照组相比叶绿素a含量、PIABS和φ_(E0)升高而ABS/RC和DI_(0)/RC降低,表明拟柱孢藻整体光合活性增加.同时,草甘膦和铅单一或联合暴露均影响了SOD和CAT活性.因此,草甘膦与铅联合暴露和单一暴露相比PSII反应中心损伤和电子传递速率抑制加大,光合效率下降更加明显,最终影响拟柱孢藻生长.
In order to explore the joint toxicity of pesticides and heavy metals on Cylindrospermopsis raciborskii,the single and joint effects of glyphosate and lead were investigated on the growth,chlorophyll a content,photosynthetic system and antioxidant enzymes in C.raciborskii.The results showed that the growth rate of C.raciborskii was significantly increased with low concentrations of glyphosate(0.7 mg·L^(-1))and lead(0.1 and 10 mg·L^(-1))exposure,while remarkably decreased with high concentrations of glyphosate(17.1 mg·L^(-1))exposure,compared with the control group.Moreover,the growth rate of glyphosate and lead combined treatment groups was significantly lower than that of single exposure group,indicating that the toxicity of joint exposure to C.raciborskii was increased than single exposure.It is found that the joint exposure of glyphosate and lead increased the initial slope of fluorescence induction curve(M0),relatively variable fluorescence(VJ),light energy absorbed by antenna pigment per unit reaction center(ABS/RC),heat dissipation energy of reaction center(DI0/RC),energy used to reduce QA(TR0/RC)and quantum ratio of energy dissipation(φD0)significantly.Joint exposure also decreased the performance index(PIABS)based on the absorption of light energy,the potential activity of PSII(FV/F0),the maximum photochemical efficiency(φ_(P0)),the probability of other electron acceptor exceeding QA in the transmission chain at t=0(ψ_(0)),and the quantum ratio for heat dissipation(φ_(E0))significantly,indicating that joint exposure can reduce the number of photosynthetic reaction centers,slow down the electron transfer rate,and cause a large accumulation of QA-.At the same time,single exposure or joint exposure affected the activities of SOD and CAT.Therefore,joint exposure of glyphosate and lead were more obvious than the single exposure to increase the damage of PS II reaction center and inhibition of electron transfer rate,and the decline of photosynthetic efficiency,which finally affected the growth of C.raciborskii.
作者
刘洋
张佳乐
牛奥迎
皇甫子依
薄业华
Sultan Yousef
张榜军
LIU Yang;ZHANG Jiale;NIU Aoying;HUANGPU Ziyi;BO Yehua;SULTAN Yousef;ZHANG Bangjun(Henan International Joint Laboratory of Aquatic Ecotoxicology and Health,College of Life Sciences,Henan Normal University,Xinxiang 453007;Journal of Henan Normal University,Xinxiang 453007;Department of Food Toxicology and Contaminants,National Research Centre of Egypt,Cairo 12622)
出处
《环境科学学报》
CAS
CSCD
北大核心
2022年第8期485-494,共10页
Acta Scientiae Circumstantiae
基金
河南省高等学校青年骨干教师培养计划(No.2021GGJS036)
国家重点研发计划“政府间国际科技创新合作”(No.2021YFE0112000)
河南师范大学研究生创新项目(No.YL202129)。
关键词
入侵生物
拟柱孢藻
草甘膦
铅
联合毒性
叶绿素荧光
invasive species
Cylindrospermopsis raciborskii
glyphosate
lead
joint toxicity
chlorophyll fluorescence
