Max Planck Institute of Molecular Plant Physiology, Energy and Central Metabolism Research Groups, D-14476 Potsdam-Golm, Germany.
Plant Physiol. 2010 Mar;152(3):1501-13. doi: 10.1104/pp.109.150045. Epub 2010 Jan 20.
The role of nitrogen metabolism in the survival of prolonged periods of waterlogging was investigated in highly flood-tolerant, nodulated Lotus japonicus plants. Alanine production revealed to be a critical hypoxic pathway. Alanine is the only amino acid whose biosynthesis is not inhibited by nitrogen deficiency resulting from RNA interference silencing of nodular leghemoglobin. The metabolic changes that were induced following waterlogging can be best explained by the activation of alanine metabolism in combination with the modular operation of a split tricarboxylic acid pathway. The sum result of this metabolic scenario is the accumulation of alanine and succinate and the production of extra ATP under hypoxia. The importance of alanine metabolism is discussed with respect to its ability to regulate the level of pyruvate, and this and all other changes are discussed in the context of current models concerning the regulation of plant metabolism.
本研究调查了氮代谢在耐长期水淹过程中的作用，以高度耐涝、结瘤的 Lotus japonicus 植物为研究对象。结果表明，丙氨酸的产生是一种关键的缺氧途径。丙氨酸是唯一一种其生物合成不受氮缺乏抑制的氨基酸，因为 RNA 干扰沉默根瘤血红蛋白会导致氮缺乏。水淹后诱导的代谢变化可以通过丙氨酸代谢的激活以及三羧酸循环途径的模块化操作来最好地解释。这种代谢情况的综合结果是在缺氧条件下积累丙氨酸和琥珀酸并产生额外的 ATP。本文讨论了丙氨酸代谢的重要性，及其调节丙酮酸水平的能力，并在当前关于植物代谢调控的模型框架内讨论了所有这些变化。
