Which of the following pigment is responsible for pink colouration in Rhizobium?

Correct option is B

· Rhizobium is a nitrogen-fixing bacterium that forms a symbiotic relationship with the roots of leguminous plants.
· The pink color in Rhizobium-infected root nodules is primarily due to the pigment Leghaemoglobin.
· Leghaemoglobin is an oxygen-binding protein found in the root nodules of legume plants.
· It plays a critical role in protecting the nitrogenase enzyme from oxygen, as nitrogenase is highly sensitive to oxygen and gets deactivated in its presence.
· Leghaemoglobin acts similarly to hemoglobin in animals, facilitating the transport of oxygen and maintaining low oxygen levels around nitrogenase.
Thus, the correct option is (b) Leghaemoglobin.