Rutin treatment delays postharvest chilling injury in green pepper fruit by modulating antioxidant defense capacity

Green peppers are highly susceptible to low-temperature stress during postharvest storage, leading to significant quality deterioration. This study aimed to elucidate the molecular mechanisms by which rutin treatment regulates metabolic pathways in green peppers under low-temperature stress. Metabolomics and transcriptomics analyses were employed to investigate the effects of rutin treatment on storage quality, reactive oxygen species (ROS) metabolism, and antioxidant levels in green peppers. Results indicated that rutin treatment maintained higher quality and firmness, suppressed increases in relative electrolyte leakage, O 2 •− production rate, and H 2 O 2 content, and mitigated chilling injury (CI). According to the transcriptomics and metabolomics analysis, a total of 4232 differentially expressed genes (DEGs) and 1929 differentially abundant metabolites (DAMs) were found to be enriched in peppers treated with rutin compared to the control group after 4 d of storage. The integrated analysis revealed that rutin treatment inhibited the occurrence of CI in green peppers by enhancing glutathione metabolism, carotenoid biosynthesis, and amino acid metabolism. Major genes and metabolites affected by rutin treatment included GGT , GPx , APX , RRM2 , CrtB , LUT5 , ABA1 , NCED , Nit4 , NOA1 , OAT , HDC , and glutathione, glutathione disulfide, dehydroascorbic acid, zeaxanthin, abscisic acid, abscisic acid glucose ester, aspartate, arginine, proline, and tyrosine. RT-qPCR verification confirmed the altered expression levels of critical genes such as GST , GPx , LUT5 , ABA1 , ASS1 , and OAT . These findings provide a theoretical basis for understanding CI regulation in green peppers and support the application of rutin in postharvest management of fruit and vegetables. • Rutin delays the onset of CI in green peppers during cold storage. • Rutin enhances ROS scavenging and mitigates oxidative damage. • Rutin enhances glutathione metabolism. • Rutin enhances carotenoid biosynthesis. • Rutin enhances amino acid metabolism.