An Amazing Union In The Soil

Today I read about an amazing union in the soil. So, nitrogen is essential for the plant growth and reproduction. But the gas has to be converted into compounds such as ammonia before vegetation can make use of it. Legumes solve this problems by working in close partnership with bacteria called rhizobia. Such a mutually beneficial union between unlike organisms is called symbiosis. By means of a special chemical, the legume attracts the bacteria to its roots, which the bacteria then enter. Although the bacteria and the plant are members of two separate kingdoms, they work together to construct what is essentially a new organ: a fully operation nitrogen-fixing root nodule. Inside the nodule, their new home and workshop, the bacteria get to work. Their main tool is a special enzyme- a form of protein called nitrogenase- which they use to fix nitrogen capture from their pockets in the soil. The planet’s entire supply of nitrogenase could fit into a single large bucket. So every molecule counts! But there is a problem. The enzyme is ruined by oxygen. The solution? The legume produces a special substance that snatches potentially harmful oxygen away. A membrane around the nodule controls the exchange of ammonia, sugars, and other nutrients between microbe and plant. Like all plants, legumes eventually die. When they do, the ammonia stays in the soil. Thus, legumes have rightly been dubbed “green manure.” As we can see, this is another evidence of a great design, constructed by an intelligent creator.