Bacteria inside root nodules need oxygen to survive. A pink or red color inside a nodule indicates the oxygen supply is robust and the bacteria are thriving. Disclaimer: AAAS and EurekAlert!

Nodules on the roots of peas and beans help the plant to secure its own nitrogen, reducing the need for artificial fertiliser. Professor Giles Oldroyd's group is researching how this could be ...

IN addition to the red pigment, hæmoglobin,· we have always found in leguminous root nodules a brown pigment. This is methæmoglobin with trivalent iron1. The simplest way of demonstrating its ...