Nitrogen fixation by leguminous plants presumably takes place when plants and mycorrhizal fungi work together. The mechanism used by plants to house rhizobial bacteria in special cells is the same as that used in their symbiosis with mycorrhizal fungi.
Leguminous plants live in symbiosis with rhizobial bacteria, which fix nitrogen from the air for the plant. Mycorrhizal fungi, which are also found in many other plants, extract nutrients from the soil for the host. Both rhizobia and mycorrhizae are absorbed by the plant cell in special tiny membrane compartments used by the plant to regulate symbiosis, postulates the group of Ton Bisseling. Their research has shown that the mechanisms used to form the compartments appear to be identical.
Therefore, many plants besides legumes have the mechanism within them to carry out symbiosis with rhizobial bacteria, conclude the molecular biologists. They now hope to apply the principle of nitrogen fixation in leguminous plants to all crops which live in symbiosis with mycorrhizial fungi. That could dispense with a great deal of artificial fertilizers.