title: Quantitative Relationship between Cadmium Uptake and the Kinetics of Phytochelatin Induction by Cadmium in a Marine Diatom.
abstract: Heavy metals activate the synthesis of phytochelatins (PCs), while the induced PCs might affect metal uptake via chelating intracellular free metals. However, the relationship of PCs to metal uptake is poorly understood. In this study, we examined the kinetics of cadmium (Cd) accumulation and the synthesis of PCs in a marine diatom, Thalassiosira weissflogii, under different irradiance levels. Irradiance alone could not change the concentrations of PCs in the Cd-free treatments, while higher irradiance accelerated the induction of intracellular PCs at the same [Cd2+] level. PC-SH (2 × PC2+ 3 × PC3+ 4 × PC4) was bound with Cd at a stoichiometric ratio of 2 to 49 in our short-term uptake experiments, indicating that PC induction is sufficient to serve as the first line of defense against Cd stress. A positive linear correlation between the induction rate of PCs and the Cd uptake rate was observed, while the ratio of the PC content to intracellular Cd varied greatly when the irradiance was increased several fold. Because metal uptake has been successfully used in predicting acute metal toxicity, our findings are helpful for understanding the role of PCs in metal detoxification and developing PCs as biomarkers for metal sensitivity.
authors: Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials (ECM), School of Environmental Science and Engineering, Nanjing University of Information Science &Technology (NUIST), Nanjing 210044, China.|Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors: Yun
authors: Y
authors: Wu
authors: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors: Zhiqiang
authors: Z
authors: Guo
authors: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors: Wei
authors: W
authors: Zhang
authors: College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
authors: Qiaoguo
authors: Q
authors: Tan
authors: Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors: Li
authors: L
authors: Zhang
authors: Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials (ECM), School of Environmental Science and Engineering, Nanjing University of Information Science &Technology (NUIST), Nanjing 210044, China.
authors: Xinlei
authors: X
authors: Ge
authors: Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials (ECM), School of Environmental Science and Engineering, Nanjing University of Information Science &Technology (NUIST), Nanjing 210044, China.
authors: Mindong
authors: M
authors: Chen
mesh_terms: D059001:Aquatic Organisms / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism*; D002614:Chelating Agents / Q000378:metabolism*; D017377:Diatoms / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D054811:Phytochelatins / Q000378:metabolism*
chemical_list: D002614:Chelating Agents; D002104:Cadmium; D054811:Phytochelatins