大豆结瘤和固氮的现代遗传学与生物技术学

大豆(Glycine max)是一种重要的供给粮食和动物饲料的主要农作物。作为豆科植物的一员，大豆与一种被称之为根瘤菌的土壤细菌形成了复杂的共生关系，结果导致新的根器官--根瘤的形成。在这个吸引人的新器官中，被植物所囚禁的根瘤菌能把空气中的氮气转换为可利用的氮肥。在巴西，有助于增加种子收成的细菌菌株借助微生物学手段已经被分离出来。目前，现代遗传学、生物技术学、生理学、生物化学和基因组学使得分离根瘤形成过程中的关键基因成为现实。 综合这些研究发现了诱导，并随后控制细胞分裂的一种新的分子机制。笔者所在的研究小组已经在大豆中克隆到了根瘤菌结瘤因子信号的关键受体，以及一些在复杂的根-茎-根信号传递途径中的分子组分，这些组分涉及到肽类激素，受体激酶和小的信号代谢产物。上述发现表明提高大豆产量和抗逆性的大豆改良进入一个新的阶段。

Modern Genetics and Biotechnology of Soybean Nitrogen Fixation and Nodulation

Soybean (Glycine max) is a major crop plant important for food supply and animal feed. Belonging to the legume family, it enters a complex symbiosis with soil bacteria called rhizobia, which results in the formation of a new root organ, the nodule. In this fascinating new organ the plant imprisoned rhizobia convert atmospheric nitrogen gas to valuable nitrogen fertiliser. Careful microbiology has isolated bacterial strains that help final seed yields as seen in Brazil. Modern genetics, biotechnology, physiology, biochemistry and genomics now have allowed the isolation of critical genes for the formation of the nodule. Together these studies indicate a novel molecular mechanism for the induction and subsequent control of cell division. Our research group has cloned the genes of two key soybean receptors for the rhizobial nodulation factor signal as well as molecular components of a complex root to shoot to root signaling loop involving peptide hormones, receptor kinases and small signaling metabolites. The findings suggest a new age of soybean improvement allowing for increased soybean yields and stress tolerance.