Immunogold localisation of hemoglobin inCasuarina root nodules

Summary Immunocytochemical localisation of hemoglobin on sections ofFrankia-infecledCasuarina glauca nodule tissue confirmed its presence in nitrogen-fixing infected cells. Using colloidal gold as the marker, hemoglobin was shown to be restricted to the cytoplasm and nucleus of infected cells. None was associated with endophyte hyphae or uninfected cells. As infection developed, with its associated thickening and modification of host cell walls, the level of label, and by implication, the level of hemoglobin increased.Abbreviations SPL semi-permeable layer - GA glutaraldehyde - PFA paraformaldehyde