Enhanced expression of CYP2C9 and tolerance to sulfonylurea herbicides in transgenic rice plants

Abstract

We compared three transgenic rice plants transformed with pIJ2C9, pIES2C9, or pIJU2C9, which express the human CYP2C9 gene under the control of the CaMV 35S, chimeric CaMV 35S, or maize polyubiquitin 1 promoter, respectively. The plants, especially those transformed with pIJU2C9, showed high tolerance to the sulfonylurea herbicides chlorsulfuron, imazosulfuron, and triasulfuron, owing to metabolic detoxification promoted by the introduced CYP2C9. The levels of expression of CYP2C9 were highly related to the tolerance to sulfonylurea herbicides. In this study, we achieved to produce transgenic rice plants with high expression of CYP2C9 by use of a maize polyubiquitin 1 promoter. Imazosulfuron is used in rice, but chlorsulfuron and triasulfuron are not, because of the sensitivity of rice plants to them. Transgenic rice plants expressing CYP2C9 will be useful for introducing tolerance to chlorsulfuron and triasulfuron into rice lines. Copyright © 2005 The Japanese Society for Plant Cell and Molecular Biology.