Regulation of Heme Biosynthesis in the Bradyrhizobium japonicum/Soybean Symbiosis

固氮大豆血红素生物合成的调控 人们正在研究根瘤， 细菌共生体大豆慢生根瘤菌与 植物调节共生所必需的代谢过程。 细菌血红素被认为是蛋白质的辅基。 植物根瘤蛋白豆血红蛋白，因此血红素和脱辅基蛋白 各组织的综合工作必须在 豆血红蛋白形成。 实验将阐明 B的作用。大豆血红素生物合成途径 豆血红蛋白的形成，并确定血红素合成基因 具体目标如下： 以（i）分离B。japonicum血红素合成突变体，（ii） 确定细菌血红素合成损伤对 豆血红蛋白合成，（iii）分离和表征B。 日本血吸虫血红素合成基因，和（iv）研究调控 血红素合成基因通过结节相关因子和 细菌调节蛋白 最后，监管 细菌血红素合成与豆血红蛋白相关 阵 生物固氮是重要的，因为它是一种 廉价且环保氮源 肥料 了解植物与微生物的相互作用 分子水平是重要的，在任何试图改善 共生或通过基因工程将其扩展到其他植物。 大豆根瘤菌与大豆互作的研究 能让我们更好地了解 沟通，并有助于身体的知识， 血红素生物合成，其中有令人惊讶的是 几乎没有遗传信息考虑到这种普遍存在的 自然中的路

The regulation of heme biosynthesis in nitrogen-fixing soybean root nodules is being studied as a means of understanding how the bacterial symbiont Bradyrhizobium japonicum interacts with the plant to regulate metabolic processes essential for symbiosis. Bacterial heme is believed to be the prosthetic group of the plant nodule protein leghemoglobin, hence heme and apoprotein synthesis by the respective orgainism must be coordinated during leghemoglobin formation. Experiments will elucidate the exact role of the B. japonicum heme biosynthetic pathway in leghemoglobin formation, and deterine how heme synthesis genes are regulated during nodule development Specific objectives are to (i) isolate B. japonicum heme synthesis mutants, (ii) determine the effects of the bacterial heme synthesis lesions on leghemoglobin synthesis, (iii) isolate and characterize B. japonicum heme synthesis genes, and (iv) study the regulation of heme synthesis genes by nodule-associated factors and by bacterial regulatory protein. Finally, the regulation of bacterial heme synthesis will be correlated with leghemoglobin formation. Biological nitrogen fixation is important because it is an inexpensive and environmentally-sound source of nitrogen fertilizer. Understanding plant-microbe interactions at the molecular level is important in any attempt to improve the symbiosis or to extend it to other plants by genetic engineering. The study of the Bradyrhizobium japonicum/soybean interaction will provide a better understanding of interkingdom commmunication as well as contribute to the body of knowledge of heme biosynthesis in general, of which there is surprisingly little genetic information considering the ubiquity of this pathway in nature.