Exogenous hydrogen sulfide delays fruit softening of kiwiberry (Actinidia arguta) during cold storage: Insights from transcriptomic analysis

• Exogenous H₂S treatment delays postharvest softening of kiwiberry. • H₂S treatment inhibits cell wall degradation of kiwiberry during cold storage. • H₂S treatment maintains higher vitamin C content in kiwiberry. • Five cell wall degradation-related genes are suppressed by H₂S treatment. • AaERFB3 and AaERFA4 are potential transcriptional regulators of kiwiberry softening. Rapid postharvest softening is a major challenge for the kiwiberry ( Actinidia arguta ) industry, as it leads to significant declines in appearance, texture, flavor, and overall quality. To reduce postharvest losses and extend shelf life, various preservation techniques have been developed. This study investigated the role of hydrogen sulfide (H 2 S), an important gaseous signaling molecule, in delaying fruit ripening and softening. Compared to the control, H 2 S-treated fruits exhibited delayed color transition, higher firmness, lower total soluble solids content, and enhanced antioxidant capacity (as evidenced by significantly increased vitamin C content). Moreover, H 2 S treatment delayed the degradation of cell wall components (e.g. hemicellulose and pectin), thereby maintaining cell wall structural integrity. Transcriptomic and RT-qPCR analyses revealed that H 2 S significantly down-regulated the expression of key cell wall degradation-related genes, including AaPG1 / 2, AaExp1, AaPLL19 , and Aaβ-Gal12 . Dual-luciferase assays further identified the H 2 S-responsive transcription factors AaERFB3 and AaERFA4 as transcriptional activator and repressor of AaPG1 and Aaβ-Gal12 , respectively . These findings reveal that H 2 S delays kiwiberry postharvest softening by modulating a transcriptional network involved in cell wall remodeling, providing a theoretical basis for developing improved kiwiberry preservation technologies.