A novel perspective on the role of long non-coding RNAs in regulating polyphenols biosynthesis in methyl jasmonate-treated Siraitia grosvenorii suspension cells

Siraitia grosvenorii (S. grosvenorii) is considered a promising economic crop due to its various bioactive compounds. Polyphenols, one of the main bioactive compounds in S. grosvenorii suspension cells, are highly beneficial for human health. Therefore, elucidating their biosynthetic regulatory mechanisms is crucial for the efficient production of these bioactive compounds. Previous studies on the regulation of plant bioactive components have more often focused on the role of protein-coding genes but overlooked non-coding genes. In this study, we provide a novel perspective on the role of long non-coding RNAs (lncRNAs) in regulating polyphenols biosynthesis in methyl jasmonate (125 mu M)-treated S. grosvenorii cells. Firstly, metabolomics analysis revealed 70 differential metabolites mainly composed of polyphenols (phenolic acids and flavonoids) in the cells. The intracellular polyphenols content (maximum 41.12 mg g-1) increased synchronously with the upregulation of polyphenols biosynthetic enzyme activity. Secondly, transcriptomics analysis indicated 496 differentiallyexpressed lncRNAs and 3595 differentially-expressed mRNAs in the cells. Besides, 29 putative regulatory pairs between differentially-expressed lncRNAs and their target mRNAs were identified, which might affect plant signal transduction, polyphenols and their precursors biosynthesis, and related transport pathways, ultimately mediating the accumulation of polyphenols in the cells. Finally, using an efficient transient transformation strategy established in this study, an antisense-lncRNA of phenylalanine ammonia-lyase (lnc-PAL) was preliminarily proven to be a negative regulatory factor on polyphenols biosynthesis in S. grosvenorii. Therefore, our findings expanded the knowledge of lncRNAs in polyphenols biosynthesis, providing a theoretical basis for the efficient production of these compounds in S. grosvenorii cells.