Transcriptome Analysis Unveils the Molecular Mechanisms of Ethylene-Induced Ready-to-Eat Kiwifruit-Picking Ripening

Kiwifruit is a climacteric fruit that undergoes significant physiological and biochemical changes during ripening, with ethylene playing a central regulatory role. Understanding the molecular mechanisms underlying ethylene-induced ripening is crucial for improving the postharvest handling and quality of ready-to-eat kiwifruit. The primary objective of the present study was to comprehensively analyze the transcriptome to investigate the ripening mechanism of ethylene-induced ready-to-eat kiwifruit. During the rapid maturation phase, it was observed that the gene Acc26812, responsible for regulating malate synthase activity, showed a significant upregulation at 84 h. Similarly, the gene Acc07097, which encodes arginine decarboxylase, also showed a significant upregulation during this period. A canonical correlation analysis (CCA) was performed to ascertain the relevance of genes associated with fruit firmness. Through transcriptome sequencing and bioinformatics analysis, approximately 2000 differentially expressed genes (DEGs) were identified. These genes were primarily involved in various pathways such as pentose and glucuronic acid interconversion, DNA replication, and others. A further investigation of these DEGs provided insights into several biological processes and molecular activities that contribute to the regulation of kiwifruit firmness. Notably, genes associated with fruit softening, including pectinesterase and cellulase, demonstrated significant upregulation, thereby indicating the degradation and remodeling of cell wall components during ripening. Additionally, highly expressed genes involved in glucose synthesis and transport highlighted the crucial role of sugar synthesis in the maturation process of ready-to-eat kiwifruit. Consequently, this study offers valuable insights into the mechanisms underlying the maturation of ready-to-eat kiwifruit.