Nitrogen is a key component of chlorophyll, which plants utilize to convert carbon dioxide and water into sugars when exposed to sunlight, nitrogen is an essential element for plants (i.e., photosynthesis).
It is also a crucial part of amino acids, which serve as the building blocks of proteins.
Plants deteriorate and perish without proteins. In the atmosphere, there is a lot of nitrogen. However, it is not possible to use it directly. It must be transformed into a usable format before use.
This is accomplished by the nitrogen fixation process, which is carried out by certain bacteria. As a result, nitrogen is converted into a form that plants may absorb through their root systems.
Bacteria get their energy from the photosynthesis of their hosts, in exchange for which they fix nitrogen into the plant, which it needs to grow and develop. This is due to their mutually beneficial partnership.