Comparative transcriptome analysis reveals the regulatory effects of exogenous auxin on lateral root development and tanshinone accumulation in Salvia miltiorrhiza

The root and rhizome of Salvia miltiorrhiza Bunge are widely used for the treatment of cardiovascular and cerebrovascular diseases in China. The root morphology and content of bioactive compounds are the main factors to determine the yield and quality of this herb. Auxin is a multifunctional phytohormone in plants and is involved in root development as well as secondary metabolites accumulation in many species, but little is known about its regulatory roles in S. miltiorrhiza. In this study, the exogenous indole-3-acetic acid (IAA) and auxin polar transport inhibitor N-1-naphthylphthalamic acid (NPA) were used to treat the S. miltiorrhiza seedlings, to investigate the regulatory roles of exogenous auxin on root development and bioactive compounds accumulation in S. miltiorrhiza