Role of sulfur assimilation pathway in cadmium hyperaccumulation by Sedum alfredii Hance.
Sedum alfredii Hance is a promising cadmium (Cd) hyperaccumulating plant recently identified in China. However, the physiological and molecular mechanisms underlying Cd accumulation, which differentiate hyperaccumulating ecotype (HE) from non-hyperaccumulating ecotype (NHE) has not been elucidated yet. A hydroponic experiment was conducted to investigate the role of sulfur assimilation pathway in Cd hyperaccumulation by the S. alfredii Hance, by analyzing gene expression pattern in sulfur assimilation pathway and the concentration of some sulfur containing compounds. The results show that, sulfur assimilation pathway was affected by Cd differently in HE and NHE S. alfredii Hance. The gene expression pattern of sulfur assimilation pathway was regulated differently in HE and NHE plants, especially the nicotianamine synthase (NAS). NAS transcript levels in root of HE was 141-fold higher than NHE, while in shoots of HE only 0.31-fold higher than NHE. In HE roots, NAS expression level was maximum 3171-fold higher than shoots, while in NHE plants roots NAS expression level was maximum 45.3-fold higher than shoots. In HE plant roots, sulfur, cysteine and methionine concentrations increased 30%, 46% and 835% respectively, by Cd treatment, but in NHE plants roots, sulfur concentration increased less than 1%, cysteine and methionine concentrations decreased 78.5% and 13.3% respectively, by Cd. Cd exposure increased glutathione levels by 142% in HE but less than 10% in NHE plant roots.
Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Jun
J
Liang
Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
M J I
MJ
Shohag
Institute of Food and Agricultural Sciences, Indian River Research and Education Center, University of Florida, Fort Pierce, FL 34945, United States; Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China. Electronic address: xyang571@yahoo.com.
Xiaoe
X
Yang
Department of Plant Sciences, University of California, Davis, CA, 95616, United States; Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Shengke
S
Tian
Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Yibin
Y
Zhang
Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Ying
Y
Feng
Institute of Food and Agricultural Sciences, Indian River Research and Education Center, University of Florida, Fort Pierce, FL 34945, United States; Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, People's Republic of China.
Zhenli
Z
He
D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D002681:China; D060146:Ecotype; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D018527:Hydroponics; D018517:Plant Roots / Q000378:metabolism; D031963:Sedum / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D013455:Sulfur / Q000378:metabolism
D012989:Soil Pollutants; D002104:Cadmium; D013455:Sulfur; D005978:Glutathione
Cadmium; Cysteine; Glutathione; Methionine; Nicotianamine synthase