Effects of a bile acid elicitor, cholic acid, on the biosynthesis of diterpenoid phytoalexins in suspension-cultured rice cells

An HPLC-ESI-MS/MS system was established for the rapid quantification of the major rice phytoalexins, phytocassanes and momilactones. It was shown that cholic acid, an elicitor of rice defense responses, preferentially induced formation of phytocassanes and the transcription of diterpene cyclase genes, including OsCPS2 (OsCyc2), that are involved in phytocassane biosynthesis in suspension-cultured rice cells.