Abscisic acid and low temperatures suppress the whole plant-specific resistance reaction of rice plants to the infection of Magnaporthe grisea

The susceptibility of rice plants to the rice blast fungus Magnaporthe grisea is increased by cold stress. However, the mechanism of this phenomenon is unknown. In this study, we found that the whole plant-specific resistance (WPSR), which was expressed in the intact leaf sheaths of susceptible rice plants, was suppressed by low temperature or abscisic acid (ABA) treatment. An inhibitor of ABA biosynthesis prevented the suppression of WPSR by low temperature treatment. These results indicate that ABA synthesized de novo under low temperature condition is a key factor for suppressing WPSR and making rice plants susceptible to M. grisea. (c) 2004 Elsevier Ltd. All rights reserved.