Leghemoglobin is a substance which is present only in the
root nodules of leguminous crops and gives pink color to
the root nodules. It facilitates the diffusion of oxygen.
The leghemoglobin pigment limits the oxygen supply to
the bacteroid. The amount of leghemoglobin and the
quantity of nodule bacteroids present together decide the
amount of nitrogen fixed by legumes. Nitrogen fixation is
an anaerobic process.
Structurally and functionally, leghemoglobin has
much in common with animal myoglobin, including its
property of binding oxygen.
