The regulatory mechanisms of delayed senescence of nitric oxide treatment of hyacinth beans

The effects of exogenous NO generated from sodium nitroprusside (SNP) on hyacinth bean have been investi-gated with metabolomic, transcriptomic, and Assay for Transposase-Accessible Chromatin with high-throughput Sequencing (ATAC-seq) analyses. Comparative analysis revealed 421 and 253 differentially accumulated me-tabolites (DAMs) in control 0 d vs control 8 d, and control 0 d vs SNP 8 d, respectively. Flavonoid biosynthesis accounted for 50% and 66% of the DAMs in the two comparative groups, respectively. The key flavonoid syn-thesis genes (PAL, CHS, CHI) were downregulated in NO treated beans. NO also downregulated genes related to cell wall degradation, lignin synthesis, plant pathogen interaction, and ethylene signal transduction. ATAC-seq analysis identified 14 co-enriched transcription factors from the ERF /DREB family, suggesting their role in regulating bean senescence. Overall, NO regulated flavonoid metabolism, cell wall degradation, lignin synthesis, plant hormones, flavonoid biosynthesis, plant pathogen interaction genes, and the ERF /DREB transcription factor family. These findings provide information about postharvest quality regulation of bean senescence.