Exploration of the effect of blue laser light on microRNAs involved in functional metabolism in D. officinale through RNA sequencing

Abstract

Dendrobium officinale has remarkable medicinal functions and high economic value. Laser light sources are different from ordinary light sources in terms of the light emission mechanism and play important roles regulating functional metabolite synthesis in D. officinale. However, the mechanism by which miRNAs participate in regulating the D. officinale response to blue laser irradiation has not been reported. Previous studies found that the number of red leaves on plants treated with blue laser light was greater than that on plants treated with blue light and white light, and blue laser light was most effective at promoting the accumulation of total flavonoids, polysaccharides and alkaloids. RNA-seq was used to analyse the difference in the effects of lasers on D. officinale. KEGG analysis of the target genes of differentially expressed (DE) miRNAs showed that there were multiple blue laser response pathways, among which peroxisome, nitrogen metabolism, terpenoid biosynthesis, porphyrin and chlorophyll metabolism played central roles. Cytoscape interaction analysis of DE miRNA targets showed that novel_miR_248 most likely participates in the influence of blue laser irradiation on D. officinale. Content verification in D. officinale showed that blue laser light could also increase the total terpene, chlorophyll levels, nitrate reductase, glutamine synthase and glutamate dehydrogenase. Combined with the qPCR results, these findings showed that miR395b, miR827 and miR319l may participate in the blue laser signalling network through their target genes and then regulate the accumulation of functional metabolites in D. officinale. This study provides a scientific basis for the high-yield production of D. officinale.