Transcriptomics analysis reveals molecular mechanism of softening and cell wall polysaccharides-disassembling in peaches treated by flow microcirculation of sodium nitroprusside medium

Peach (Prunus persica L. Batsch. var. compressa Bean) is prone to softening during storage, and this leads to a marked deterioration in quality and shortened shelf life. The influences of sodium nitroprusside (SNP) atomization on softening development, cell wall ultrastructure, cell wall polysaccharides metabolism in peach fruit stored at 0 ± 0.5 °C for 60 d were explicated. SNP atomization treated fruit, when contrasted to the control, exhibited higher firmness, contents of chelate-soluble pectin (CSP), sodium carbonate-soluble pectin (SSP), cell wall materials (CWM), cellulose and hemicellulose (HC), but lower water-soluble pectin (WSP) content. SNP treatment suppressed activities of cell wall-degrading relevant enzymes, the disassembly of cell wall structure, and the decomposition of middle lamella and plasma membrane in peach fruit. The RNA sequencing results suggested that the differentially expressed genes from amino sugar metabolic process (beta-D-xylosidase, BXL), galactose metabolism (beta-galactosidase, β-Gal), pentose and glucuronate interconversions (polygalacturonase, PG), cellular carbohydrate metabolic process (xyloglucan- endotransglucosylase/hydrolase, XTH), and expansin (Exp) were associated with cell wall degradation in peaches with aerosolized water (control) or SNP treatments. Based on these results, the delayed softening of peaches with SNP atomization was ascribed to cell wall polysaccharides degradation regulated by gene expression levels and enzymes.