Summary Autophagy is a conserved degradation pathway that regulates the clearance of paternal substrate at the early embryogenesis stage of animals. However, its mode of action is likely different in plants, which can regenerate through apomixis without fertilisation. Somatic embryogenesis (SE) is a unique plant process widely used for plant propagation and germplasm utilisation. Here, we studied citrus as an example and found a higher autophagic activity after SE initiation. Interestingly, amyloplasts were frequently found inside autophagosomes, whereas the inhibition of autophagy blocks amyloplasts/starch degradation and hinders somatic embryo formation. Furthermore, the consumption of storage lipids was faster in autophagy mutants, suggesting lipid metabolism is activated when starch utilisation is blocked. Exogenous application of autophagy‐inducing chemicals (e.g. spermidine) significantly promoted the formation of autophagosomes and increased SE efficiency, indicating a positive correlation between autophagy, energy metabolism, and somatic embryo formation in citrus. Taken together, our study unveils a pathway for the degradation of plant‐specific organelles and provides an effective approach for plant propagation.

中文翻译：

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自噬通过调节支链淀粉降解和脂质稳态对柑橘体胚发生至关重要


摘要 自噬是一种保守的降解途径，可调节动物早期胚胎发生阶段父系底物的清除。然而，它的作用方式在植物中可能有所不同，植物可以在不施肥的情况下通过 apomixis 再生。体细胞胚胎发生 （SE） 是一种独特的植物过程，广泛用于植物繁殖和种质利用。在这里，我们以柑橘为例进行研究，发现 SE 启动后具有更高的自噬活性。有趣的是，淀粉质体经常出现在自噬体内部，而对自噬的抑制会阻止淀粉质体/淀粉降解并阻碍体细胞胚胎的形成。此外，自噬突变体中储存脂质的消耗更快，这表明当淀粉利用受阻时，脂质代谢被激活。外源性施用自噬诱导化学物质（如亚精胺）显著促进了自噬体的形成，提高了 SE 效率，表明柑橘自噬、能量代谢和体胚形成之间存在正相关关系。综上所述，我们的研究揭示了植物特异性细胞器降解的途径，并为植物繁殖提供了一种有效的方法。