Binding studies of the avrXa10 gene product from Xanthomonas oryzae pv. oryzae to the promoter of a defense-response peroxidase gene.

Abstract

Xanthomonas orzyae pv. orzyae , the causal agent of the bacterial blight in rice, interacts in a race-specific manner with rice cultivars containing different resistance genes. Xanthomonas orzyae pv. orzyae containing the AVRXal0.Fl protein is known to elicit a hypersensitive response (HR) in rice cultivars containing the resistance gene Xa-10, but not on cultivars lacking Xa-10 gene. Recent research has shown that there is possible interaction of the AVRXal0 protein and the peroxidase promoter of the avrXa10 gene. In the present work, the binding of the AVRXal0 gene product from Xanthomonas orzyae pv. orzyae to the promoter of a rice defense-response peroxidase gene was studied. The peroxidase encoded by this gene is known to be a component of the defense response. The AVRXa10.Fl protein was isolated from Escherichia coli containingpET-avrXa10.F1and identified by western blot.The binding of this protein to the PCR-amplified and 5' end-labeled 117.10/3.5 promoter region of a defense-response peroxidase gene was tested by mobility shift assay. The results showed possible binding of the AVRXal0.Fl protein to the promoter region of the peroxidase gene. This finding provides insight into the mechanism of disease resistance and plant-bacteria interactions.