Biosynthesis and Regulatory Mechanisms of Bioactive Compounds in Salvia miltiorrhiza, a Model System for Medicinal Plant Biology

Salvia miltiorrhiza is one of the most well known species in the genus Salvia of the Lamiaceae with great economic, academic and medicinal value. It was recorded as a traditional Chinese medicine material first in about the second century BC and later in many other ancient books. Salvia miltiorrhiza can be clinically used alone or mixed with other herbs to treat heart and cardiovascular diseases and is beneficial for management of many other diseases. In the last 30 years, S. miltiorrhiza has been studied intensively as a model system for medicinal plant biology. With the available of whole genome sequence of four S. miltiorrhiza lines and a large number of transcriptome, sRNAome and metabolome data, great progresses have been made in biosynthesis and regulatory mechanisms of bioactive compounds, such as tanshinones, phenolic acids, flavonoids, and prenylquinones. In this review, the recent results in the biosynthetic pathways of bioactive compounds in S. miltiorrhiza were summarized. The effects of biotic and abtiotic factors, plant hormones, transcription factors and noncoding RNAs on bioactive compound biosynthesis were overviewed. The mechanism of cross-talk and coordination among different biosynthetic pathways and the progress of metabolic engineering and synthetic biology for various bioactive compounds are also reviewed and discussed.