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

Abstract

The effects of exogenous NO generated from sodium nitroprusside (SNP) on hyacinth bean have been investigated with metabolomic, transcriptomic, and Assay for Transposase-Accessible Chromatin with high-throughput Sequencing (ATAC-seq) analyses. Comparative analysis revealed 421 and 253 differentially accumulated metabolites (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 synthesis 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.