Nitrogen-fixing nodules on roots of a tree lupin, Lupinus arboreus, caused by Rhizobium bacteria. The association between Rhizobium species and legumi
Nitrogen-fixing nodules on roots of a tree lupin, Lupinus arboreus, caused by Rhizobium bacteria. The association between Rhizobium species and leguminous plants is an example of symbiosis (mutual benefit). The bacteria enter the plant roots and induce the formation of a tumour-like outgrowth, or nodule. Within the nodule, the bacteria proliferate and develop the ability to fix atmospheric nitrogen. This fixed nitrogen is beneficial to the plant for its growth, and the bacterium benefits from carbon compounds made by the plant. Nitrogen fixation involves the use of leghaemoglobin, an iron-containing protein analogous to haemoglobin. This gives the nodules a pinkish picture shows nodules of various sizes. Tree lupins are perennial plants that develop thick secondary roots ( vertical axis in the picture). The largest nodules in this pictures are approximately 1cm in diameter
Size: 3460px × 5200px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: arboreus, bacteria, biological, biology, botanical, botany, fixation, leghaemoglobin, leguminous, lupin, lupinus, nitrogen, nodule, plant, rhizobium, root, secondary, symbiosis, tree
