Figure 4.48 Leghemoglobin in nitrogen fixing nodules. The pink colour in the centre of the nodule (arrows) originates from the presence of leghemoglobin in the nitrogen-fixing zone of mature nodules. Leghemoglobin binds oxygen inside the nodules to protect the activity of nitrogenase. It also transports oxygen. Magnification bar = 1 mm. (Photograph courtesy U. Mathesius)