Studies on stem nodulation and regulatory mechanism of nitrogen fixation in Aeschynomene indica.

1.以大豆根瘤固氮酶和豆类血红蛋白为靶标，制备了大豆根瘤固氮抗体，研究了大豆根瘤固氮的调节机制。野生稻茎瘤和根瘤的固氮酶与固氮酶抗体高度交叉反应，沉淀线完全融合。然而，Aeschynomene与大豆根瘤之间的沉淀线并未完全融合。这些结果表明，水稻根瘤和茎瘤中的固氮酶与大豆根瘤中的固氮酶有较高的同源性和部分同源性。大豆根瘤中针对其蛋白制备的高铁血红蛋白抗体与大豆根瘤提取液不能产生良好的交叉反应。光和向寄主植物供应较高浓度的氮素对水稻茎结瘤的影响很小。但茎的结瘤受温度的影响，在20℃时明显受到抑制，茎中部成功形成茎瘤，说明茎的结瘤与皮孔的发育密切相关。接种来自田菁、花生和含羞草的根瘤菌，不能在水稻上形成茎瘤。

1. Antibodies were prepared against nitrogenase and leghemoglobin of soybean nodules to study the reguratory mechanism of dinitrogen fixation in Aeschynomene indica. Nitrogenase of stem and root nodules in A. indica highly crossreacted with the nitrogenase antibody and the precipitin lines completely fused. However, the precipitin lines between Aeschynomene and soybean nodules did not completely fuse. These results suggest that nitrogenases of stem and root nodules in A. indica are highly homologous and are partially homologous with that in soybean nodules. Leghemoglobin antibody prepared against its proteins in soybean nodules did not crossareact well with the nodule extract from A. indica.2. Stem nodulation in A. indica was little affected by light and the supply of higher concentration of nitrogen to the host plants. However, stem nodulation was influenced by temperature and was significantly depressed in 20 C. Stem nodules were successfully formed in the middle portion of the stem, suggesting that stem nodulation is closely related with the development of lenticels.3. Inoculation of rhizobia derived from Sesbania, Arachis, and Mimosa did not form stem nodules in A. indica.