The concentration and distribution of haemoglobin in the root nodules of leguminous plants

Abstract

Hemoglobin in legume nodules is contained only in the large bacteria-containing cells and does not appear in detectable amts. until these cells have been differentiated. The concn. in the bacteria-containing cells of nodules of different legume spp. varied between 1 and 5 x 10-4 M. After cell differentiation the concn. did not appear to vary with size of nodule. As reported by Virtanen, hemoglobin could not be detected in nodules produced by ineffective strains of Rhizobium. The amt. of hematin in such nodules, estimated as pyridine hemochromogen, was much less than that in effective nodules. Effective and ineffective strains of Rhizobium grown in pure culture differ little in the ratios of hematin/cell N.