A tissue-specific profile of miRNAs and their targets related to paeoniaflorin and monoterpenoids biosynthesis in Paeonia lactiflora Pall. by transcriptome, small RNAs and degradome sequencing

Molecular mechanism of miRNA mediated biosynthesis of secondary metabolites in medicinal plants

Plant secondary metabolites are important raw materials for the pharmaceutical industry, and their biosynthetic processes are subject to diverse and precise regulation by miRNA. The identification of miRNA molecules in medicinal plants and exploration of their mechanisms not only contribute to a deeper understanding of the molecular genetic mechanisms of plant growth, development and resistance to stress, but also provide a theoretical basis for elucidating the pharmacological effects of authentic medicinal materials and constructing bioreactors for the synthesis of medicinal secondary metabolite components. This paper summarizes the research reports on the discovery of miRNA in medicinal plants and their regulatory mechanisms on the synthesis of secondary metabolites by searching the relevant literature in public databases. It summarizes the currently discovered miRNA and their functions in medicinal plants, and summarizes the molecular mechanisms regulating the synthesis and degradation of secondary metabolites. Furthermore, it provides a prospect for the research and development of medicinal plant miRNA. The compiled information contributes to a comprehensive understanding of the research progress on miRNA in medicinal plants and provides a reference for the industrial development of related secondary metabolite biosynthesis.

Multi-omics analysis of small RNA, transcriptome, and degradome to identify putative miRNAs linked to MeJA regulated and oridonin biosynthesis in Isodon rubescens

Isodon rubescens has garnered much attention due to its anti-tumor or anti-cancer properties. However, little is known about the molecular mechanism of oridonin biosynthesis leveraging the regulatory network between small RNAs and mRNAs. In this study, the regulatory networks of miRNAs and targets were examined by combining mRNA, miRNA, and degradome. A total of 348 miRNAs, including 287 known miRNAs and 61 novel miRNAs, were identified. Among them, 51 miRNAs were significantly expressed, and 36 miRNAs responded to MeJA. A total of 3066 target genes were associated with 228 miRNAs via degradome sequencing. Multi-omics analysis demonstrated that 27 miRNA-mRNA pairs were speculated to be involved in MeJA regulation, and 36 miRNA-mRNA pairs were hypothesized to be involved in the genotype-dependence of I. rubescens. Furthermore, 151 and 7 miRNA-mRNA modules were likely engaged in oridonin biosynthesis as identified by psRNATarget and degradome sequencing, respectively. Some miRNA-mRNA modules were confirmed via RT-qPCR. Moreover, miRNAs targeting plant hormone signal transduction pathway genes were identified, such as miR156, miR167, miR393, and PC-3p-19822_242. Collectively, our results demonstrate for the first time that miRNAs are identified in I. rubescens, and laid a solid foundation for further research on the molecular mechanism of oridonin biosynthesis mediated by miRNA.