SNP treatment enhances carbohydrate and secondary metabolite accumulation in postharvest Dendrobium officinale:...

Following harvest, the medicinal quality of Dendrobium officinale declines due to ongoing metabolism. This study applied sodium nitroprusside (SNP) treatment and used biochemical and transcriptomic analyses to investigate its effects. Results showed that 400 μmol L^-1 SNP increased soluble sugars, proteins, antioxidant capacity, and stress resistance. Transcriptomic analysis revealed upregulation of MAN, PFK, PFP, and GMD, correlating with a 163% increase in polysaccharides, while downregulation of ALDO, TREH, and ENPP reduced cellulose and starch. Upregulation of F3H, CHS, and HCT boosted flavonoids and polyphenols, and upregulation of MVK, PAL, COMT, 4CL, and CYP73A led to a 179% rise in dendrobine. Transcription factors ERF, MYB, and WRKY were also implicated. SNP treatment redirected carbon allocation from starch/cellulose to bioactive polysaccharides and promoted dendrobine and flavonoid accumulation, thereby enhancing medicinal quality. This study offers new strategies for maintaining postharvest quality in medicinal plants.