AUTHOR=Chen Peilei , Wei Xiaoyan , Qi Qianting , Jia Wenjing , Zhao Mingwei , Wang Huina , Zhou Yanqing , Duan Hongying 

TITLE=Study of Terpenoid Synthesis and Prenyltransferase in Roots of Rehmannia glutinosa Based on iTRAQ Quantitative Proteomics

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.693758

DOI=10.3389/fpls.2021.693758

ISSN=1664-462X

ABSTRACT=<p><italic>Rehmannia glutinosa</italic> has important medicinal value; terpenoid is one of the main active components in <italic>R. glutinosa</italic>. In this study, iTRAQ technique was used to analyze the relative abundance of proteins in roots of <italic>R. glutinosa</italic>, and 6,752 reliable proteins were quantified. GO enrichment results indicated that most proteins were involved in metabolic process or cellular process, 57.63% proteins had catalytic activity, and 65.80% proteins were enriched in membrane-bounded organelle. In roots of <italic>R. glutinosa</italic>, there were 38 KEGG enrichments with significance, more DEPs were found in some pathways, especially the proteasome pathway and TCA cycle with 15.0% DEPs between elongation stage and expansion stage of roots. Furthermore, five KEGG pathways of terpenoid synthesis were found. Most prenyltransferases belong to FPP/GGPP synthase family, involved in terpenoid backbone biosynthesis, and all interacted with biotin carboxylase CAC2. Compared with that at the elongation stage, many prenyltransferases exhibited higher expression at the expansion stage or maturation stage of roots. In addition, eight FPP/GGPP synthase encoding genes were cloned from <italic>R. glutinosa</italic>, namely <italic>FPPS, FPPS1, GGPS, GGPS3, GGPS4, GGPS5, GPPS</italic> and <italic>GPPS2</italic>, introns were also found in <italic>FPPS, FPPS1, GGPS5</italic> and <italic>GGPS2</italic>, and FPP/GPP synthases were more conservative in organisms, especially in viridiplantae, in which the co-occurrence of GPPS or GPPS2 was significantly higher in plants. Further analysis found that FPP/GGPP synthases of <italic>R. glutinosa</italic> were divided into three kinds, GGPS, GPPS and FPPS, and their gene expression was significantly diverse in different varieties, growth periods, or tissues of <italic>R. glutinosa</italic>. Compared with that of <italic>GGPS</italic>, the expression of <italic>GPPS</italic> and <italic>FPPS</italic> was much higher in <italic>R. glutinosa</italic>, especially at the expansion stage and maturation stage. Thus, the synthesis of terpenoids in roots of <italic>R. glutinosa</italic> is intricately regulated and needs to be further studied.</p>