Transcriptome analysis reveals mechanisms of acetylsalicylic acid-mediated fruit quality maintenance in fresh-cut kiwifruit

Postharvest ripening and processing of fresh-cut (FC) kiwifruit brings quality deterioration and spoilage, including substantial changes in fruit color, texture and flavor. Hence, a series of preservation techniques have emerged to reduce postharvest loss and maintain FC kiwifruit quality. In this study, we evaluated the efficacy of acetylsalicylic acid (ASA), a derivative of plant endogenous hormone salicylic acid, in preserving the quality and delaying the ripening process of FC kiwifruit. Compared to the control fruit, ASA treatment maintained a better fruit appearance and higher fruit firmness, as well as reducing mass loss, total soluble solids and ethylene production. Based on the RNA-seq data and weighted gene co-expression network analysis (WGCNA), eight biosynthetic genes were identified as involved in fruit quality change, which participates in cell wall metabolism, starch degradation/sugar accumulation and ethylene biosynthesis. Moreover, the analysis showed that four transcription factors were significantly induced by exogenous ASA treatment. Dual-luciferase assays proved that ASA-responsive transcription factors regulated fruit quality-related genes, resulting in delaying ripening process and extending the shelf-life of FC kiwifruit. This study showed that ASA effectively delayed the ripening process, and AcWRKY7/AcDOF21/AcC2H2–151/AcbHLH123 are associated with the ASA-mediated fruit quality maintenance.