From Model to Crop: Roles of Macroautophagy in Arabidopsis and Legumes

Leguminous plants are critical global crops for food security, animal feed, and ecological sustainability due to their ability to establish nitrogen-fixing symbioses with rhizobia and their high nutritional value. Autophagy, a highly conserved eukaryotic catabolic process, mediates the degradation and recycling of cytoplasmic components through the fusion of autophagosome with vacuole/lysosome and plays essential roles in plant growth, stress adaptation, and cellular homeostasis. This review systematically summarizes current knowledge of autophagy in both Arabidopsis and leguminous plants. We first outline the conserved molecular machinery of autophagy, focusing on core autophagy-related (ATG) genes in Arabidopsis and key legume species such as Glycine max, Arachis hypogaea, Pisum sativum, Cicer arietinum, and Medicago truncatula. Furthermore, the review dissects the intricate molecular regulatory networks controlling autophagy, with an emphasis on the roles of phytohormones, transcription factors, and epigenetic modifications. We then highlight the multifaceted physiological functions of autophagy in these plants. Additionally, a preliminary analysis of the ATG8 gene family in peanut indicates that its members may be involved in seed development, biological nitrogen fixation, and drought resistance. Finally, it highlights key unresolved challenges in legume autophagy research and proposes future research directions. This review aims to provide a comprehensive theoretical framework for understanding the unique regulatory mechanisms of autophagy in legumes and to provide insights for molecular breeding aimed at developing stress-resilient, high-yielding, and high-quality legume cultivars.