论文部分内容阅读
自然界的植物,都需要从外界摄取营养物质赖以生存,其中最主要的是氮素。氮在空气中大量存在,几乎占地球大气的百分之八十,可是不能被植物直接吸收,必须经过加工,使之转化成氨后,植物才可吸收利用。但有些植物,如豆科植物,却有转氨作用的特殊功能。在它们的根部长有许多根瘤菌与之共生,这种根瘤菌能摄取空气中的氮并使之转化成氨,为植物直接吸收利用。这种固氮作用,人们称之谓生物固氮。
Plants in nature need nutrients from the outside world to survive, the most important of which is nitrogen. Nitrogen is abundant in the air and accounts for almost 80% of the Earth’s atmosphere. However, it can not be directly absorbed by plants and must be processed to convert it into ammonia before the plants can be absorbed and utilized. However, some plants, such as legumes, have a special function of transaminase. In their root long symbiotic rhizobia, this Rhizobium can take in the air of nitrogen and make it into ammonia, for direct absorption and utilization of plants. This nitrogen fixation, people call biological nitrogen fixation.