CLONING, MOLECULAR CHARACTERIZATION AND HETEROLOGOUS EXPRESSION OF A GLUTATHIONE S-TRANSFERASE GENE IN RICE^§

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*Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China;
**Department of Biology, Chongqing Three Gorges University, Chongqing 404000, China.

Received November 29, 2010; in final form, December 13, 2010

OsGSTL2 is one of three tandem-arranged glutathione S-transferase, lambda class genes in chromosome 3 of rice (Oryza sativa L.). It includes 9 introns and 10 exons, and encodes a protein of 244 amino acid residues with a calculated molecular mass of 27.37 kDa. The predicted three-dimensional structure of OsGSTL2 showed a typical glutathione S-transferase fold. Using semi-quantitative RT-PCR analysis, OsGSTL2 transcript was detected in the roots and leaves of seedling stage and tillering stage, and the roots, leaves and panicles of heading stage from rice plants, and the expression level of OsGSTL2 mRNA in rice roots show significant change under chlorsulfuron stress. The OsGSTL2 gene was cloned into pYTV vector and was transformed into yeast strain PEP4. Western blot analysis showed the exogenous OsGSTL2 was expressed in transformed yeast. GST activity of crude extracts of yeast showed the OsGSTL2 transgenic yeast had higher levels of GST activities than control yeasts. These ﬁndings suggested that the OsGSTL2 is a glutathione S-transferase and has potential use in detoxification.

Key words: heterologous expression, glutathione S-transferase, GST activity, Oryza sativa L., semi-quantitative RT-PCR.

^§After author’s corrections in conformity with reviewer’s comments (remarks), the paper is published without any other editor's revision.