What type of symbiotic relationship do legumes form with specific bacteria?

Legumes form a mutualistic relationship with certain bacteria, particularly those in the genus Rhizobium. In this symbiotic relationship, the bacteria reside in root nodules of the legume plants and provide the plants with essential nitrogen in a form that they can utilize for growth. In return, the legumes supply the bacteria with carbohydrates and a suitable environment for their growth and reproduction. This mutual exchange of nutrients benefits both organisms, highlighting the mutualistic nature of their interaction.

In contrast, other types of symbiotic relationships such as parasitic or commensal involve different interactions where one organism benefits at the expense of the other or one organism benefits without affecting the other, respectively. Predator-prey relationships describe interactions where one organism, the predator, captures and feeds on another organism, the prey, which is not applicable in the context of legumes and bacteria. This makes the mutualistic relationship the most accurate description of the interaction between legumes and their symbiotic bacteria.