The site of heme synthesis in soybean root nodules

By separating breis derived from soybean plant root nodules into soluble and particulate components and incubating each with δ-amino[4−14C]levulinic acid, it was found tha: (I) The heme synthesized by the nodules is principally the product of the particulate component. (2) The particulate component is predominantly bacteriods and is devoid of plant mitochondria. (3) Some of the heme synthesized in the breis is incorporated into leghemoglobin. We conclude that bacteroids in the nodules are responsible for the major part of the synthesis of heme for leghemoglobin.