What does root nodule mean

Although the word "tumor" is included in the name of root nodule, it is actually not a disease, but a normal root symptom. It mainly refers to those roots that appear like tumor-like rhizomes in order to absorb nitrogen from air raids, so they are called root nodules. Plants with such roots generally have a stronger ability to accumulate nitrogen and are more powerful in growth and development than other plants.

Root Nodules

Nodules are special tumors that grow on plant roots, formed by nitrogen-fixing bacteria that establish symbiosis in parasitic tissues. Used to synthesize its own nitrogen-containing compounds (such as proteins, etc.), some people in the cultural and artistic circles currently prefer nodules.

form

There is a large amount of molecular nitrogen in the air, which accounts for about 80% of the air composition. It is estimated that there are about 4×1015 t of molecular nitrogen in the entire atmosphere. However, most plants can only absorb bound nitrogen from the soil to synthesize their own nitrogen-containing compounds (such as proteins, etc.). Nitrogen-containing compounds in the soil are not inherent in the soil itself, but are gradually accumulated in the process of biological life activities, a large part of which comes from biological nitrogen fixation by microorganisms. It is estimated that the total amount of biological nitrogen fixation on the earth's surface is about 10 tons per year, of which the amount of nitrogen fixed by rhizobia in leguminous plants is about 5.5×10 t, accounting for about 55% of the total amount of biological nitrogen fixation.

Making a difference

Rhizobia rapidly divide and multiply in the cortical cells. At the same time, the cortical cells also rapidly divide and grow due to the stimulation of the invasion of nodules, causing the local volume of the roots to swell and form tumor-like protrusions, which are nodules. Rhizobia absorb the water and nutrients they need for life from nodule cells. They can fix free nitrogen and synthesize nitrogen-containing compounds for use by leguminous plants. The symbiosis between legumes and rhizobia results in high yields due to the nitrogen they obtain; at the same time, due to the shedding of nodules, the nodular roots or stumps left in the soil can increase soil fertility. Using leguminous plants as green manure or rotating or intercropping them with other rhizobia of soybeans can significantly increase production. Leguminous plants can fertilize the fields due to the nitrogen-fixing function of rhizobia.