Systemic acquired resistance plays a major role in bacterial blight resistance in a progeny of somatic hybrids of cultivated rice (Oryza sativa L.) and wild rice (Oryza meyeriana L.)

As the number of people in the world increases, people's demand for food becomes greater. In order to reduce reliance on pesticides that maintain crop yields, plant disease resistance is gaining increasing attention. As a near-isogenic line with high resistance to bacterial blight, transcriptional regulation of Y73 on disease resistance has aroused our great interest. To comprehend how Y73 plants defend themselves against bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) and how their disease resistance is executed at the transcriptional level, a time series transcriptional profiles of the local leaves and systemic leaves of Y73 and its recurrent parent Dalixiang (DLX) were obtained after inoculation with Xoo strain PXO341. Transcriptome data showed that the differences between incompatible (Y73 to Xoo) and compatible (DLX to Xoo) interactions were greater in the systemic leaves than in the inoculated ones. In contrast to compatible interactions, incompatible interactions were able to generate a sustained systemic acquired resistance (SAR) response, groups of genes like PR3 (chitinase 5) and PR1 had been up-regulated in systemic leaves. These results provide evidence that a robust and sustained SAR response in Y73 plays an important role in its broad-spectrum and high resistance to bacterial blight.