Angermann Cecile, Heinemann Björn, Nogueira Bianca Bueno, Mai Hans-Jörg, Bauer Petra, Hildebrandt Tatjana M
Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47a, 50674, Cologne, Germany.
Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil.
Plant J. 2025 Jul;123(2):e70357. doi: 10.1111/tpj.70357.
Efficient nutrient mobilization from seed storage tissues is essential for seedling establishment, particularly in legumes such as Lupinus albus (white lupin), which thrive in nutrient-poor soils. This study investigates the role of cotyledons in nitrogen (N) and mineral remobilization after germination during their transition from storage organs to photosynthetically active tissues, including the metabolic challenges posed by the coexistence of these two functions in epigeal germination. We cultivated white lupin seedlings under nitrogen-deficient conditions, analyzing cotyledon composition and function over 28 days. Our results indicate that 60% of cotyledon-stored proteins are degraded within the first 8 days, with free amino acids transiently accumulating before being redistributed to support growth. The progressive depletion of cotyledon reserves was accompanied by structural and metabolic changes, including an increase in photosynthetic proteins. However, cotyledon photosynthetic capacity remained lower than that of true leaves, suggesting a transient role in energy metabolism. The loss of cotyledons before day 12 significantly impaired seedling development, emphasizing their critical contribution to nitrogen, phosphate, and micronutrient supply during early growth. Comparative proteomic analysis revealed dynamic shifts in nutrient transport, amino acid metabolism, and stress response pathways following cotyledon removal. These findings underscore the significance of cotyledon nutrient remobilization in legume adaptation to low-fertility soils and highlight potential targets for breeding strategies aimed at improving nutrient use efficiency. By optimizing cotyledon nutrient composition and function, future breeding efforts could enhance seedling vigor, reduce fertilizer dependency, and improve the nutritional value of lupin-based foods.
从种子储存组织中高效动员养分对于幼苗的建立至关重要，特别是在诸如白羽扇豆（Lupinus albus）等豆科植物中，它们能在养分贫瘠的土壤中茁壮成长。本研究调查了子叶在萌发后从储存器官转变为光合活性组织过程中对氮（N）和矿物质再动员的作用，包括在地上萌发过程中这两种功能共存所带来的代谢挑战。我们在缺氮条件下培养白羽扇豆幼苗，分析子叶在28天内的组成和功能。我们的结果表明，60%的子叶储存蛋白在最初8天内被降解，游离氨基酸在重新分配以支持生长之前短暂积累。子叶储备的逐渐消耗伴随着结构和代谢变化，包括光合蛋白的增加。然而，子叶的光合能力仍低于真叶，表明其在能量代谢中起短暂作用。在第12天之前去除子叶会显著损害幼苗发育，强调了它们在早期生长过程中对氮、磷和微量营养素供应的关键贡献。比较蛋白质组学分析揭示了去除子叶后养分运输、氨基酸代谢和应激反应途径的动态变化。这些发现强调了子叶养分再动员在豆科植物适应低肥力土壤中的重要性，并突出了旨在提高养分利用效率的育种策略的潜在目标。通过优化子叶的养分组成和功能，未来的育种工作可以提高幼苗活力，减少对肥料的依赖，并提高基于羽扇豆的食品的营养价值。
