摘要
运用叶绿素荧光技术分析了盐胁迫和重金属镉(Cd)对蛋白核小球藻(Chlorella pyrenoidosa)光系统Ⅱ(PSⅡ)的影响理.实验中小球藻培养基设置NaCl浓度梯度分别为0、25、100 mmol/L,然后在不同NaCl浓度的培养基中再加入CdCl2溶液,使培养基中Cd2+的浓度分别为0、1、25、100μmol/L.在处理后的1、3、6、12、24 h测定其快速上升荧光曲线和荧光参数.实验发现,高浓度的NaCl(≥25 mmol/L)和Cd(≥25μmol/L)会降低PS的活性,降低应中度.NaCl抑制了依赖于光的应,降低了光能捕获和用于电子传递的量子产额.Cd作用于应中,增加了单应中吸收的光能和用于热耗散的能量.较低浓度(1μmol/L)的Cd处理对小球藻PS活性有作用.NaCl和Cd的处理均体现了时间和浓度的依赖性.盐胁迫和Cd胁迫体现了随浓度增高加重彼此胁迫强度的协同作用的特点.
The effects of NaCl and cadmium （Cd） on photosystem Ⅱ （PSⅡ） activity of Chlorella pyrenoidosa were investigated by chlorophyll fluorescence test to detect the changes of PSⅡ performance caused by environmental stress. NaCl concentrations in media were set as 0, 25 and 100 mmol/L and CdCl2 concentrations in media were 0, 1, 25 and 100 μmol/L. The fluorescence parameters were detected after exposure for 1, 3, 6, 12 and 24 h, respectively. The results showed that the
PSⅡ efficiency and the number of reaction centers decreased under stresses of high levels of NaCl （≥25 mmol/L） and Cd （≥25 μmol/L）. The inhibition of NaCl was more related to the light dependent reaction by decreasing the quantum yield for electron transport. The main target site of Cd was the PSⅡ reaction center by increasing the absorbed energy and dissipation in each reaction center. The PSⅡ activity was enhanced by low concentration Cd （1 μmol/L）. The effects of NaCl and Cd depended on their concentrations and exposure time, which had synergistically inhibitory effects on PSⅡ activity. Fig 7, Tab 1, Ref 28
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2011年第6期839-846,共8页
Chinese Journal of Applied and Environmental Biology
基金
中国科学院知识创新工程重方向性项目(No.KZCX2-YW-335)、中国科学院“百人计划”项目
国家自然科学基金项目(No.40673070)资助~~
关键词
蛋白核小球藻
盐胁迫
镉胁迫
叶绿素荧光
光系统Ⅱ(PSⅡ)
Chlorella pyrenoidosa, salt stress, cadmium stress, chlorophyll fluorescence, photosystem Ⅱ （PSⅡ）
