FUNCTIONAL CHARACTERIZATION AND GENETIC ENGINEERING OF RICE TAL EFFECTOR-DEPENDENT R GENE Xa10

Abstract

Bacterial blight of rice, caused by gram-negative bacteria Xanthomonas oryzae pv. oryzae (Xoo), is one of the most severe bacterial diseases affecting rice worldwide. Xa10 is a rice bacterial blight resistance (R) gene, which confers race-specific resistance to Xoo strains harboring TAL effector AvrXa10. In this study, we show that once induced or expressed, Xa10 triggers programmed cell death in the absence of pathogens. XA10 is an ER membrane protein that interacts with itself and may form hexamers on the ER membrane. Xa10-mediated PCD is associated with ER Ca2+ depletion in Nicotiana benthamiana. In addition, transgenic rice plant Xa10E5NB, which has broad-spectrum and durable resistance, is generated by genetic engineering of the Xa10 promoter. These results provide new insights into the functional mechanism of the R gene in inducing disease resistance to pathogens.