Regulatory mechanisms for anthocyanin biosynthesis in chemotypes of Perilla frutescens var. crispa

In Perilla frutescens, the expression of all structural anthocyanin genes is coordinately regulated by light in form-specific manner in aerial vegetative tissues. To find the regulatory factors for entire anthocyanin pathway in dicot plants, the red form specifically expressed genes were profiled by mRNA differential display. As a result, a novel bHLH factor gene Myc-F3G1 was isolated. The deduced amino acid sequence of MYC-F3G1 exhibited high homology with that of petunia and, which directly regulates the expression of anthocyanin structural genes. The expression of Myc-F3G was detected specifically in red form but not in green form and induced by light induction. These expression patterns are similar to those of structural anthocyanin genes and Myb-P1, a light-inducible Myb gene. In yeast two-hybrid systems, MYC-F3G1 interacted with another bHLH factor MYC-RP and a WD40 repeat protein PFWD but not with a light-inducible Myb factor Myc-P1. These results suggest that a protein complex including MYC-F3G1, MYC-RP, Myb-P1 and PFWD regulates the expression of anthocyanin biosynthetic genes in P frutescens. These findings shall provide valuable information for genetic engineering of entire anthocyanin pathway in dicot plants. (C) 2003 Elsevier Science B.V. All rights reserved.