Abstract

Plant glutathione S-transferases (GSTs) have been a focus of attention because of their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice. Transgenic rice plants overexpressing OsGSTL2 were generated from rice calli by the use of an Agrobacteriumtransformation system. The transgenic rice plants were screened by a combination of hygromycin resistance, polymerase chain reaction (PCR) and Southern blot analysis. Transgenic rice plants overexpressing OsGSTL2 gene showed higher levels of OsGSTL2 transcripts in the absence of any treatment compared to non-transformed rice plants. In the vegetative tissues of transgenic rice plants, the overexpression of the OsGSTL2 increased levels of GST and glutathione peroxidase (GPX) activities, and reduced content of superoxide. Transgenic rice plants also had higher tolerance to glyphosate and chlorsulfuron, which often contaminates agricultural fields. These findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crop plants for developing herbicides tolerance and in limiting herbicides availability in the food chain.

Key words: Glutathione S-transferase, transgenic rice, overexpression, herbicide resistance.