Abstract
In paddy field, phytochrome double mutants, phyAphyB, appeared more susceptible to fungi than wild type. In order to investigate the possible roles of phytochromes in defense responses, rice (Oryza sativa L. cv. Nipponbare) seedlings of phyA and phyAphyB mutants were inoculated with the compatible rice blast fungus (Pyricularia oyzae). PhyAphyB showed more serious disease symptoms than phyA. Moreover, the inoculation with fungus induced rapider and higher accumulation of several PR proteins in phyA than in phyAphyB. The crosstalks between phytochromes signaling with Jasmonic Acid (JA) and Salicylic acid (SA) pathway were examined by analyzing expression of defense-related genes in rice seedlings of phyA and phyAphyB treated with exogenous JA or SA.
