マメ科植物における水およびリン利用効率の遺伝的改良

为提高磷缺乏条件下豆科作物的产量，对固氮机理进行了研究。我们的研究结果如下：1。短叶紫花苜蓿固氮是通过与磷胁迫下根瘤碳代谢密切相关的n反馈机制介导的。揭示了天冬酰胺在下调植物固氮能力中的关键作用。在缺磷条件下，截根草的共生固氮量高于苜蓿，这与提高根瘤中有机酸浓度即苹果酸盐的能力有关。鹰嘴豆共生体效率的提高与有机酸生成能力和与根瘤碳氮代谢相关的关键酶活性的增强有关。

We have studied mechanisms of N_2 fixation with the aim to enhance legume crop productivity under phosphonls (P) deficiency. Our findings are as follows :1. N_2 fixation in Medicago truncatula is mediated through an N-feedback mechanism that is closely related to nodule carbon metabolism under P stress. The critical role of asparagine in the down-regulation of N_2 fixation was revealed.2. M. truncatula had a higher symbiotic N_2 fixation than M. sativa under P deprivation conditions, which was related to the ability to increase the organic acid concentration in nodules, namely malate.3. The improved efficiency in chickpea symbiois was associated with the enhanced capacity of organic acid formation and the activities of the key enzymes related to the nodule carbon and nitrogen metabolisms.