Localization of Sucrose Synthase in Soybean Root Nodules

Immunogold labelling studies using polyclonal antibodies to sucrose synthase suggest that this enzyme is exclusively located in the cytoplasm of soybean nodule cells. A significantly greater intensity of labelling was found in the cytosol of uninfected interstitial cells of the central nodule region compared with the cytosol of the infected cells. Labelling was low in the bulk of the cortical cells but was found to be high in the vascular endodermis and in the cortical cells between the bundle and the infected region. The results are discussed in relation to carbohydrate supply and metabolism and in the context of nodule structure.