Immunogold localization of VuFeSOD. A, Labeling in the cytosol of infected cells (arrows). There is some minor nonspecific labeling of bacteroids. B, Labeling in the cytosol of uninfected cells (arrows). C, Serial section to A that was incubated in non-immune serum. Note the absence of significant labeling. b, Bacteroid; w, cell wall; s, starch; px, peroxisome. Bars = 500 nm.