The SmERF1b-like was involved in tanshinone biosynthesis of Salvia miltiorrhiza hairy root

Abstract

Abstract Ethylene response factor (ERF) play an important role in the regulation of secondary metabolism in Salvia miltiorrhiza. Here, an AP2/ERF gene (named SmERF1b-like) was cloned from the cDNA library of S. miltiorrhiza. The SmERF1b-like had the ERF conserved domain，and it was highly expressed in leaves. It was responded to exogenous ethylene treatment. SmERF1b-like enriched in the nucleus. SmERF1b-like was bond to the GCC-box in the promoter of key tanshinones biosynthesis gene in S. miltiorrhiza. In the SmERF1b-like overexpressed hairy roots, the expression level of SmERF1b-like, SmCPS1 and SmKSL1 were significantly up-regulated, and the contents of tanshinone I and tanshinone IIA were significantly increased. While the SmERF1b-likegene silenced, the gene expression level and the content of tanshinones were not significantly different with overexpressed SmERF1b-like. It is showed that SmERF1b-like had the genetic function redundancy in biosynthesis regulation of tanshinone. Above all, SmERF1b-like recognized the GCC-box of key gene promoter in nucleus to promote the biosynthesis of tanshinone. This study provides the theoretical support for the use of plant genetic engineering strategies to improve S. miltiorrhiza resources.