Molecular mechanism of Pb1-mediated panicle blast resistance in rice

Background In Japan, an average of 22 billion yen is spent annually for agrochemicals in order to control rice damage caused by the blast disease. Thus, blast resistance is one of the most important targets of rice breeding. Several blast resistance genes have been identified so far. However, many of them are effective against particular races of blast fungi only and the resistance against the blast disease is often lost by breakdown within a few years. The Panicle blast 1 (Pb1) gene has been utilized for rice breeding because of its durability. However, the reason for the durability has been unknown. It is therefore necessary to clarify the molecular mechanism involved in Pb1-mediated resistance against blast so that it can be used efficiently and safely in the future. In this study, we investigated the relationship of Pb1 with WRKY45, the central transcription factor involved in induced disease resistance of rice.