Abstract
Jasmonates (JAs) are plant-specific key signaling molecules that respond to various stimuli and are involved in the synthesis of secondary metabolites. However, little is known about the JA signal pathway, especially in economically significant medicinal plants. To determine the functions of novel genes that participate in the JA-mediated accumulation of secondary metabolites, we examined the metabolomic and transcriptomic signatures from Salvia miltiorrhiza. For the metabolome, 35 representative metabolites showing significant changes in rates of accumulation were extracted and identified. We also screened out 2131 differentially expressed unigenes, of which 30 were involeved in the phenolic secondary metabolic pathway, while 25 were in the JA biosynthesis and signal pathways. Among several MeJA-induced novel genes, SmJAZ8 was selected for detailed functional analysis. Transgenic plants over-expressing SmJAZ8 exhibited a JA-insensitive phenotype, suggesting that the gene is a transcriptional regulator in the JA signal pathway of S. miltiorrhiza. Furthermore, this transgenic tool revealed that JAZ genes have novel function in the constitutive accumulation of secondary metabolites. Based on these findings, we propose that the combined strategy of transcriptomic and metabolomic analyses is valuable for efficient discovery of novel genes in plants.
Highlights
IntroductionIn S. miltiorrhiza, Luo et al.[20] reported 7 candidate cytochrome P450s which may be involved in the tanshinone and phenolic acid biosynthesis by investigating methyl jasmonate (MeJA)-induced gene expression profiles
As part of our first step, we report here our comprehensive analysis of the impact that methyl jasmonate (MeJA) has on S. miltiorrhiza along with a phenotype description, transcriptome data, and results from the metabolomic analysis
By combining metabolomic and transcriptomic analysis, terpenoid metabolism were demonstrated to display a biphasic response to elicitation[23], and a potential role for the induced MeJA-responsive transcription factor was found
Summary
In S. miltiorrhiza, Luo et al.[20] reported 7 candidate cytochrome P450s which may be involved in the tanshinone and phenolic acid biosynthesis by investigating MeJA-induced gene expression profiles. Integrated analyses of the metabolomes and transcriptomes of Arabidopsis[21] and tomato[22] have already led to the discovery of several new genes with special functions This approach was utilized to characterize the inducible nature of tanshinone production in hairy root cultures of S. miltiorrhiza[23]. Transgenic analysis suggested its potential role in JAZ-regulated secondary metabolism, based on significantly increased levels of salvianolic acid B (Sal B) measured in the transgenics These findings will help in further establishing an efficient strategy as “phenotype-transcriptome-metabolome” for discovering novel genes in those economically significant medicinal plants. We performed GC/MS-based profiling for primary metabolites as well as phenolic- and tanshinone-targeted analyses by LC/MS
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
