Heteroexpression of the wheat phytochelatin synthase gene (TaPCS1) in rice enhances cadmium sensitivity  

作　　者：Feijuan Wang Zhubing Wang Cheng Zhu 

机构地区：[1]Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China [2]College of Life Sciences, Zhejiang University, Hangzhou 310058, China

出　　处：《Acta Biochimica et Biophysica Sinica》2012年第10期886-893,共8页生物化学与生物物理学报(英文版)

摘　　要：Phytochelatin synthase (PCS) (EC 2.3.2.15) catalyzes the final step of phytochelatins (PCs) biosynthesis. PCs are a family of cysteine-rich thiol-reactive and heavy metal- binding peptides that play an important role in sequestra- tion and detoxification of heavy metals in plants. Previous studies have indicated that plants that overexpressed PCS displayed contrasting phenotypes, ranging from enhanced cadmium (Cd) tolerance to Cd hypersensitivity in Arabidopsis thaliana. In this study, the wheat phytochela- tin synthase gene, TaPCS1, was heteroexpressed in wild- type rice (Oryza sativa L., cv. Zhonghua 11) to evaluate the relationship between synthesis of PCs and Cd toler- ance in rice. Data showed that the heteroexpression of TaPCSI in rice enhanced Cd sensitivity and significantly increased Cd accumulation in shoots, but not in roots. Additionally, the PCS line exhibited a much higher content of PCs and non-protein thiols (NPTs) in shoots. Prominent changes in NPT composition led to reduced glutathione pool depletion and higher Cd content in cell organelles in shoots, followed by higher oxidative stress, which might result in Cd sensitivity. Therefore, the hetero- expression of TaPCS1 in rice is capable of increasing Cd accumulation in rice shoots and enhancing Cd sensitivity.Phytochelatin synthase (PCS) (EC 2.3.2.15) catalyzes the final step of phytochelatins (PCs) biosynthesis. PCs are a family of cysteine-rich thiol-reactive and heavy metal- binding peptides that play an important role in sequestra- tion and detoxification of heavy metals in plants. Previous studies have indicated that plants that overexpressed PCS displayed contrasting phenotypes, ranging from enhanced cadmium (Cd) tolerance to Cd hypersensitivity in Arabidopsis thaliana. In this study, the wheat phytochela- tin synthase gene, TaPCS1, was heteroexpressed in wild- type rice (Oryza sativa L., cv. Zhonghua 11) to evaluate the relationship between synthesis of PCs and Cd toler- ance in rice. Data showed that the heteroexpression of TaPCSI in rice enhanced Cd sensitivity and significantly increased Cd accumulation in shoots, but not in roots. Additionally, the PCS line exhibited a much higher content of PCs and non-protein thiols (NPTs) in shoots. Prominent changes in NPT composition led to reduced glutathione pool depletion and higher Cd content in cell organelles in shoots, followed by higher oxidative stress, which might result in Cd sensitivity. Therefore, the hetero- expression of TaPCS1 in rice is capable of increasing Cd accumulation in rice shoots and enhancing Cd sensitivity.

关 键 词：CADMIUM GLUTATHIONE sensitivity RICE phytochelation 

分 类 号：X171[环境科学与工程—环境科学] Q945.78[生物学—植物学]