INDUCTION OF XA 27 BY THE AVRXA27 GENE IN RICE CONFERS BROAD- SPECTRUM RESISTANCE TO XANTHOMONAS ORYZAE PV. ORYZAE AND ENHANCED RESISTANCE TO XANTHOMONAS ORYZAE PV. ORYZICOLA
The present invention generally provides a method to generate broad-spectrum resistance to bacterial blight disease in plants. More specifically, the present invention provides a method to generate broad-spectrum resistance to Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight disease of rice, and enhanced resistance to Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak of rice. Xa27, an inducible bacterial blight R gene in rice, was induced by the cognate avrXa27 gene expressed in host. Rice plants carrying the avrXa27 transgene and wild-type Xa27 gene conferred resistance to incompatible and compatible pathogens, and enhanced resistance to X. oryzae pv. oryzicola strain L8. The Xa27-mediated enhanced resistance to X. oryzae pv. oryzicola was also observed in the interaction between IRBB27 and L8 harboring pHM1avrXa27. This was further verified by the fact that the Xa27 gene in IRBB27 was induced by theavrXa27 gene in bacteria. The method can be used to engineer broad-spectrum resistance of rice to bacterial blight and enhanced resistance to bacterial leaf streak. Slight modification of this technique can be applied to control bacterial diseases in other crops. WO2008094127A1
