Autophagy modulates the degradation and recycling of intracellular materials and contributes to male gametophyte development and male fertility in plants. However, whether autophagy participates in seed development remains largely unknown. Here, we demonstrate that autophagy is crucial for timely programmed cell death (PCD) in the integumentary tapetum, the counterpart of anther tapetum, influencing embryo pattern formation and seed viability. Inhibition of autophagy resulted in delayed PCD of the integumentary tapetum and defects in embryo patterning. Cell-type-specific restoration of autophagic activities revealed that the integumentary tapetum plays a non-autonomous role in embryo patterning. Furthermore, high-throughput, comprehensive lipidomic analyzes uncovered an unexpected seed-developmental-stage-dependent role of autophagy in seed lipid metabolism: it contributes to triacylglycerol degradation before fertilization and to triacylglycerol biosynthesis after fertilization. This study highlights the critical role of autophagy in regulating timely integumentary tapetum PCD and reveals its significance in seed lipid metabolism and viability.

自噬调节细胞内物质的降解和回收，有助于植物雄性配子体的发育和雄性育性。然而，自噬是否参与种子发育仍然很大程度上未知。在这里，我们证明自噬对于外皮绒毡层（花药绒毡层的对应物）的及时程序性细胞死亡（PCD）至关重要，影响胚胎模式的形成和种子活力。自噬的抑制导致外皮绒毡层 PCD 延迟和胚胎图案缺陷。细胞类型特异性的自噬活性恢复揭示了外皮绒毡层在胚胎模式中发挥非自主作用。此外，高通量、全面的脂质组学分析揭示了自噬在种子脂质代谢中意想不到的种子发育阶段依赖性作用：它有助于受精前三酰甘油的降解和受精后三酰甘油的生物合成。这项研究强调了自噬在调节及时地皮绒毡层 PCD 中的关键作用，并揭示了其在种子脂质代谢和活力中的重要性。