Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response. However, the role of autophagy in fruit ripening is largely unknown. Here, we demonstrated that most autophagy-related genes () were up-regulated during tomato ( L.) fruit ripening. By using mutants of different autophagy pathway genes (, , ), we revealed that the deficiency of autophagy delayed the ripening of fruit. Compared with wild-type (WT), the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in mutants during fruit ripening. We also observed the contents of glucose and fructose were both significantly decreased in mutants compared with WT, while the content of organic acids showed the opposite trend. Additionally, the negative regulator of ethylene production, APETALA2a (AP2a), interacted with ATG8 through a specific ATG8-interacting motif (AIM) and could be degraded through the autophagy pathway. These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments, sugars and organic acids in tomato.

中文翻译：

---

自噬调节乙烯合成通过影响番茄中番茄红素、糖和有机酸的积累介导果实成熟


自噬是真核生物中普遍的细胞过程，在植物生长和应激反应中发挥着关键作用。然而，自噬在果实成熟中的作用很大程度上未知。在这里，我们证明大多数自噬相关基因 () 在番茄 (L.) 果实成熟过程中上调。通过使用不同自噬途径基因的突变体（，，，），我们揭示了自噬缺陷延迟了果实的成熟。与野生型（WT）相比，突变体在果实成熟过程中乙烯产生显着减少，番茄红素积累延迟。我们还观察到与WT相比，突变体中葡萄糖和果糖的含量均显着降低，而有机酸的含量则呈现相反的趋势。此外，乙烯产生的负调节因子 APETALA2a (AP2a) 通过特定的 ATG8 相互作用基序 (AIM) 与 ATG8 相互作用，并可通过自噬途径降解。这些结果表明，自噬通过调节番茄中乙烯的产生以及色素、糖和有机酸的积累，在果实成熟中发挥着关键作用。