Involvement Of Jasmonic Acid In Chitin Elicitor-induced Defense Responses In Suspension-cultured Rice Cells

Abstract

In suspension-cultured rice cells, chitin elicitor treatment induces defense responses, such as production of pathogenesis-related proteins and phytoalexins. Although jasmonic acid (JA) has been suggested to be involved in some of these elicitor-induced defense responses, physiolosical functions of JA in rice defense responses are largely unknown. In this study, by microarray analysis, elicitor-induced genes in suspension-cultured cells were compared between normal-type rice and cpm2, a photomorphogenesis mutant that is thought to be JA-deficient, to investigate the roles of JA in the elicitor-induced defense responses. The results show the expression of 720 genes of 3384 elicitor-induced genes identified in the normal-type rice cells were suppressed in cpm2. The genes suppressed in cpm2 include those coding for phytoalexin biosynthesis enzymes, transcription factor involved in JA signaling, JA biosynthesis enzymes, and phospholipid-metabolizing enzymes. It was also shown that elicitor-induced phytoalexin production was suppressed in cpm2.