[Responses of jasmonates and tanshinones in Danshen to mechanical wounding induction]

When plants are subjected to mechanical wounding(MW)caused by insect feeding, extreme weather, and human factors, they rapidly initiate a series of response mechanisms at the transcriptional and metabolic levels, leading to changes in the content of phytohormone and secondary metabolites in plants. In this study, using the medicinal model plant Danshen(Salvia miltiorrhiza) as an example, the effect of MW on the metabolism of medicinal plants was evaluated. By virtue of qRT-PCR and LC-MS, the changes in the biosynthetic genes and contents of jasmonates(JAs) and tanshinones in response to leaf damage stimulation were detected to reveal the related patterns of transcription and metabolism in leaves and roots at different time points after MW treatment, thus exploring the response mechanism of Danshen to MW stress. The results showed that MW induction could transiently increase the expression of biosynthetic genes of Jas, with AOC and JAR beginning to increase and peaking at 2 h after induction, while AOS and OPR3 peaked at 4 h. Correspondingly, the content of OPDA, JA, and JA-Ile all peaked at 2 h. In the biosynthesis of tanshinones, the diterpene synthase genes CPS1 and KSL1 both peaked at 2 h, while the subsequent modification genes CYP450s all peaked at 4 h. The content of the four tanshinones showed a continuous increase trend within 8 h. This study provides a reference for revealing the research on secondary metabolite accumulation under MW stress and lays a foundation for further understanding the role of Jas in enhancing plant resistance, promoting the accumulation of active ingredients, and improving the quality of medicinal materials under MW stress.