Autophagy-mediated energy charge sustainability alleviated postharvest quality deterioration of strawberry (Fragaria × ananassa)

Fluctuations in energy status are critical physiological factors influencing postharvest fruit quality. However, the role of autophagy, a stress-resistant biological process, in regulating postharvest fruit energy status remains unclear. In this study, we treated strawberry fruit with the autophagy inhibitor hydroxychloroquine (HCQ) to investigate the role of autophagy in maintaining energy status. The results demonstrated that HCQ treatment inhibited autophagosome formation, reducing relative autophagic activity by 73 % on day 6. HCQ treatment also reduced the energy charge and the NADH/NAD⁺ ratio by 5 % and 61 %, respectively, on day 2. Corresponding to the decline in energy status, HCQ treatment led to a reduction in cytochrome C oxidase (CCO) and succinate dehydrogenase (SDH) activities by 47.48 % and 56.34 %, respectively, on day 3. Additionally, fluctuations in energy charge led to abnormalities in ripening and decreased stress resistance in autophagy-inhibited fruit. In conclusion, this study provides evidence that autophagy-mediated energy charge sustainability mitigates postharvest quality deterioration in fruit.