Effects of Salicylic Acid on the Expression of SOD,PPO Isozymes and NPR1 in Pear Construction of pepper CaNPR1-RNAi expression vector and its transformation to pepper Over-expression of Arabidopsis thaliana AtNPR1 gene in rice enhances the rice resistance to bacterial blight and blast diseases Transferring disease resistance gene NPR1 into Siraitia grosvenorii