AUTHOR=Dai Yiqun , Ye Ziyu , Liu Hui , Zhu Ruirui , Sun Lanlan , Li Shuai , Xie Guoyong , Zhu Yan , Zhao Yucheng , Qin Minjian 

TITLE=The chemical profiling of Salvia plebeia during different growth periods and the biosynthesis of its main flavonoids ingredients

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1228356

DOI=10.3389/fpls.2023.1228356

ISSN=1664-462X

ABSTRACT=<p><italic>Salvia plebeia</italic> (Lamiaceae) is a valuable medicinal plant widely distributed across Asia and Oceania. However, the composition and accumulation patterns of its active ingredients in different organs during the growth and their biosynthetic mechanism remain unknown. Therefore, we conducted metabolite profiling, transcriptomic analysis, and biological functional verification to explore the distribution, accumulation, and biosynthesis mechanisms of flavonoids in <italic>S. plebeia.</italic> We identified 70 metabolites including 46 flavonoids, 16 phenolic acids, seven terpenoids, and one organic acid, of which 21 were previously unreported in <italic>S. plebeia</italic>. Combining metabolomic-transcriptomic analysis and biological functional verification, we identified the key genes involved in biosynthesis of its main active ingredients, hispidulin and homoplantaginin, including <italic>SpPAL</italic>, <italic>SpC4H</italic>, <italic>Sp4CL2</italic>, <italic>Sp4CL5</italic>, <italic>SpCHS1</italic>, <italic>SpCHI</italic>, <italic>SpFNS</italic>, <italic>SpF6H1</italic>, <italic>SpF6OMT1</italic>, <italic>SpF6OMT2</italic>, <italic>SpUGT1</italic>, <italic>SpUGT2</italic>, and <italic>SpUGT3</italic>. Using the identified genes, we reconstructed the hispidulin and homoplantaginin biosynthesis pathways in <italic>Escherichia coli</italic>, and obtained a yield of 5.33 and 3.86 mg/L for hispidulin and homoplantaginin, respectively. Our findings provide valuable insights into the changes in chemical components in different organs of <italic>S. plebeia</italic> during different growth and harvest stages and establishes a foundation for identifying and synthesizing its active components.</p>