Archivio Journal of Plant Pathology

Abstract:

In this study, we investigated pathogenesis-related (PR) protein expression in interactions between rice plants with bacterial blight resistant gene Xa21 and Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial blight. Three PR genes, OsPR1a, OsPR1b, and OsPR10a, were cloned and the fusion proteins were expressed in E. coli to generate polyclonal antibodies. The proteins isolated at 0, 12, 24, 36, 48, 60, 72, and 144 h post-inoculation (hpi) from rice leaves inoculated with incompatible Xoo strains were analyzed using Western blotting. Significant inductions were observed for all three PR proteins in the late stages of inoculation. We also compared the expression of PR proteins among four different modalities: (i) incompatible interactions (R); (ii) compatible interactions in the absence of the Rgene (SR -); (iii) compatible interactions in the absence of the avirulence factor in Xoo (SAvr -); (iv) mock inoculated control treatments (M). Results showed that the three PR proteins are enhanced in the R, SR -, and SAvr - interactions more than in the control treatments. The induction of PR proteins in the R interaction is the highest, suggesting that these proteins are involved in the defense mechanism.