Abstract
Saponins are suger-modified triterpene derivatives. In oats, the saponin was implicated as determinants of the resistance to the root-infecting fungus Gaeumannomyces graminis. We were not able to detect the saponins and the intermediates in rice using LC/MS and GC/MS. Our final goal is that the anti-microbial saponin is available for the rice. Therefore, to be clear this secondary metabolite biosynthesis pathway in rice, we are performing molecular analyses. First, we focused one of the pivotal genes, OxidoSqualene Cyclases (OsOSCs), on the pathway, and performed gene expression and evolution analyses. Here, we report that we found eleven OsOSC homologues in the rice genome using the DNA sequence data from oats and rice. Five out of eleven were likely to pseudogenes from the genome structures and the data of gene expression analyses. Other five genes out of eleven were expressed. We are going to measure their enzymatic activity in next step.
