Overexpression of rice premnaspirodiene oxygenase reduces the infection rate of Xanthomonas oryzae pv. oryzae

Plants utilize cytochrome P450, a large superfamily of heme-containing mono-oxygenases, in the synthesis of lignins, UV protectants, pigments, defense compounds, fatty acids, hormones, and signaling molecules. Despite the overwhelming assortment of rice P450 accession numbers in the database, their functional studies are lacking. So far, there is no evidence involving rice P450 in disease immunity. Most of our understanding has been based on other plant systems that are mostly dicot. In this study, we isolated the cytochrome P450 (OsCYP71) in rice, and screened the gene using gain-of-function technique. The full-length cDNA of OsCYP71 was constitutively overexpressed using the 35S promoter. We then explored the functions of OsCYP71 in the rice - Xanthomonas oryzae pv. oryzae pathosystem. Using the gene expression assays, we demonstrate the interesting correlation of PR gene activation and the magnitude of resistance in P450-mediated immunity.