?-Aminobutyric acid treatment induced chilling tolerance in postharvest kiwifruit (Actinidia chinensis cv. Hongyang) via regulating ascorbic acid metabolism

The effect of gamma-Aminobutyric acid (GABA) treatment on ascorbic acid (AsA) metabolism and chilling injury in postharvest kiwifruit was studied. The results revealed that kiwifruit treated with GABA displayed higher chilling tolerance and better quality maintenance as compared to the controls. Higher AsA was observed in GABA-treated fruit which was beneficial to cell membrane protection and damage alleviation against chilling mediated oxidative stress. Gene expression analysis found the increased expression of AsA anabolic and regenerative genes and down-regulation of its catabolic genes together could contribute to the elevation of AsA levels in kiwifruit after GABA treatment. In addition, the transcripts of several candidate transcription factors such as bHLHs and HZ1 involved in AsA biosynthesis were also enhanced by GABA treatment. Collectively, our results indicated that GABA induced chilling tolerance in postharvest kiwifruit due to the higher AsA content by positively regulating ascorbate metabolic genes and candidate transcription factors.

Automated summary

The effect of GABA treatment in postharvest kiwifruit was studied, and it was found that GABA treatment resulted in higher chilling tolerance and better quality maintenance. This was attributed to the increase in AsA levels, which helped protect cell membranes and alleviate chilling-induced oxidative stress. GABA treatment also upregulated the expression of AsA metabolic genes and candidate transcription factors involved in AsA biosynthesis.