Research Project
Grant-in-Aid for Scientific Research (C)
We found that two P450 genes (CYP99A2 and CYP99A3) and a putative dehydrogenase gene (AK103462) forms a gene cluster on chromosome 4 of the rice genome together with two diterpene cyclase genes that are involved in biosynthesis of momilactones. In addition, the five clustered genes were coordinately induced after treatment with a chitin oligosaccharide elicitor in suspension-cultured rice cells, suggesting that the momilactone biosynthesis genes are clustered on chromosome 4.On the basis of the above background, this project aimed to demonstrate the presence of a momilactone biosynthetic gene cluster and elucidate regulatory mechanisms for coordinate expression of the gene cluster. We indicated that AK103462 encodes momilactone A synthase, and that the double knockdown of CYP99A2 and CYP99A3 specifically suppressed the elicitor inducible production of momilactones. We thus demonstrated that a momilactone biosynthetic gene cluster consisting of four or five genes is present on chromosome 4 in rice. In addition, we identified an elicitor-inducible basic leucine zipper (bZIP) transcription factor, OsTGAP1, which coordinately regulates the expression of all five genes in the momilactone biosynthetic gene cluster. We also showed that OsTGAP1 can influence the expression of a phytocassane biosynthetic gene and an upstream methylerythritol phosphate (MEP) pathway gene. We thus indicated that OsTGAP1 functions as a key regulator of the coordinated transcription of genes involved in inductive diterpenoid phytoalexins production in rice.All the studies presented here give us important basic information to clarify regulatory mechanisms for production of diterpenoid phytoalexins in rice.
All 2009 2008 2007 2006 Other
All Journal Article (5 results) (of which Peer Reviewed: 3 results) Presentation (25 results)
J.Biol.Chem. 284(印刷中)
J.Biol.Chem. 282
Pages: 34013-34018
The Journal of Biological Chemistry 282
J.Biol.Chem. (in press)
