Abstract

Soft rot, caused by Botryosphaeria dothidea , is a major postharvest disease of kiwifruit, leading to substantial economic losses in the kiwifruit industry. The study sought to explore how exogenous ferulic acid (FA) treatment could enhance disease resistance and preserve postharvest quality in kiwifruit, while also seeking to understand the underlying regulatory mechanisms. The results indicated that 0.8 g L −1 FA reduced the colony diameter of B. dothidea in vitro and the lesion diameter of B. dothidea -inoculated kiwifruit. Additionally, FA treatment lowered the respiration rate, reduced postharvest weight loss, delayed the decrease in flesh firmness, and maintained higher levels of total soluble solids and titratable acidity in kiwifruit. Moreover, FA boosted the activities and gene expressions of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase, as well as the levels of ascorbic acid and glutathione. Furthermore, FA increased the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, and reduced the levels of malondialdehyde and hydrogen peroxide, as well as the rate of superoxide anion production. By upregulating the activities and gene expressions of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, 4-coumaric acid coenzyme A ligase, and cinnamyl alcohol dehydrogenase, FA concurrently increased the levels of total phenolics, flavonoids, and lignin. Additionally, FA heightened the activities and gene expressions of chitinase and β-1,3-glucanase. Overall, FA effectively enhanced resistance to B. dothidea by inducing antioxidative and phenylpropanoid metabolism, thereby safeguarding the quality of postharvest kiwifruit.