Metabolomic and transcriptomic integration analysis reveals the effect of 1-methylcyclopropene on regulating phenylpropanoid metabolism and improving fruit quality in ‘Danxiahong’ pears after cold storage and during shelf-life

Extended low-temperature storage severely impairs the fruit quality of ‘Danxiahong’ pears ( Pyrus bretschneideri ) , a cultivar that holds high economic value due to its excellent quality. Pretreatment with 1-methylcyclopropene (1-MCP) fumigation delayed peel yellowing, inhibited fruit softening, and preserved overall quality during a four-month cold storage period and subsequent 12 day shelf-life. Metabolomic analysis revealed that during these two storage processes, 1-MCP predominantly regulated phenylpropanoid metabolites. The gene expression levels and enzymatic activities of upstream enzymes in the phenylpropanoid pathway were increased by 1-MCP, this led to higher levels of phenolic acids and flavonoids, and improving the free radical scavenging capacity. Additionally, 1-MCP enhanced antioxidant enzyme activities and reduced membrane lipid peroxidation. Concurrently, 1-MCP suppressed the gene expression of pectin and cellulose degradation enzymes, reducing their enzymatic activities and maintaining fruit firmness. In addition to inhibiting ethylene biosynthesis, 1-MCP exerts regulatory effects on the expression of genes involved in abscisic acid, gibberellin, and auxin signaling. Collectively, this study integrates metabolomic, transcriptomic, and physiological analyses to reveal the effect of 1-MCP treatment on improving fruit quality in ‘Danxiahong’ pears after long-term cold storage followed by shelf-life, and providing new insights for optimizing postharvest preservation strategies for this cultivar.