DR.JEREMY BURGESS / SCIENCE PHOTO LIBRARY DR.JEREMY BURGESS / SCIENCE PHOTO LIBRARY
Macrophotograph of pink nodules of the nitrogen- fixing bacteria Rhizobium leguminosarum on the roots of a pea plant (Pisum sativum). The nodules are the sites where the bacteria fix atmospheric nitrogen and convert it into an organic form which is used by the plant in the synthesis of proteins and nucleic acids. The bacteria live freely in the soil, and will accumulate around fine root hairs, probably in response to some attractant exuded by the root. The nodule is pink because of the presence of haemoglobin, whose function is uncertain but is known to be necessary to nitrogen fixation. Magnification: X 1 at 35mm size.
Model release not required. Property release not required.