A STUDY OF LEGHEMOGLOBIN LOCALIZATION IN YELLOW LUPIN NODULES

Leghemoglobin localization was studied by immunochemical, cytochemical, and biochemical methods in the ultrathin sections of nodule tissues and in the isolated subcellular compartments from the root nodules of yellow lupin (Lupinus luteus L., cv. Fakel) after inoculation with the effective Bradyrhizobium lupini strain 359a. Colloid gold-labeled antiserum against leghemoglobin and 3,3'-diaminobenzidine were employed for electron-microscope analysis. With intact structure maintained in the peribacteroid membrane, leghemoglobin was found in the cytosol of the plant cells of the nodule and was absent from the peribacteroid space and the bacteroids. Thus, we have validated the view that leghemoglobin found in the peribacteroid space represented an artifact resulting from its transfer from the cytosol through the damaged peribacteroid membrane.