They are caused by a symbiotic bacteria which benefits the plant by fixing atmospheric nitrogen (which the plant needs to make proteins).
Nitrogen. :) (All proteins must contain nitrogen. Legumes such as peas and beans are high in protein because they share a mutualistic relationship with Rhizobium bacteria in the soil. The bacteria give the plant nitrogen in the form of nitrate ions in exchange for glucose from the root nodules.) -Izzie. (Hope this helped!!)
The nitrogen-fixing bacteria live in the root nodules of legumes.
Rhizopus bacteria is found in the roots of legumes
Special class of bacteria called Rhizomes live on the roots of leguminus plants. They take free nitrate and nitrites from the environment and change to a form that can be readily used by plants. Relationship between nitrogen fixing bacteria and plants is called Symbiosis.
nitrogen fixation, like legumes
Legume plants are notable for their ability to fix atmospheric nitrogen, thanks to a symbiotic relationship with certain bacteria known as rhizobia found in root nodules of these plants. The ability to form this symbiosis reduces fertilizer costs for farmers and gardeners who grow legumes, and allows legumes to be used in a crop rotation to replenish soil that has been depleted of nitrogen. The nitrogen fixation ability of legumes is enhanced by the availability of calcium in the soil and reduced by the presence of ample nitrogen. Root nodules. via Wikipedia
what is nitrogen fixing bacteria live in these structures found in the roots of legumes
legumes
rhizobium
nitrogen-fixing bacteria
Legumes have nirtifying bacteria in their roots, but mostly they are found in the soil.
Rhizobium.