Construction of transgenic rice plants in which the expression of jasmonic acid biosynthesis genes is suppressed by RNA interference method

Abstract

Jasmonic acid (JA) is known to be an important signaling molecule in defense response against wounding. JA is synthesized in the octadecanoid pathway, which employs several enzymes including allene oxide synthase (AOS), allene oxide cyclase (AOC), and 12-oxo-phytodienoic acid reductase (OPR). We generated transgenic rice plants in which the expression of the genes encoding AOS, AOC, and OPR (OsAOS, OsAOC, OsOPR1 and OsOPR3 ) is suppressed by RNAi method. JA content in leaves of the OsAOS-suppressed transformant was reduced approximately 62% of the wild-type level. JA content was undetectable in leaves of the OsAOC-suppressed transformant. JA content in leaves of the OsOPR1-and OsOPR3-co-suppressed transformant was reduced approximately 3% of the wild-type level. These materials will provide a useful tool to elucidate the functions of the intermediates (e.g., 12-oxo-phytodienoic acid) of the octadecanoid pathway in rice defense responses.