3.6. Immunolabeling of anti-nitrogenase
Immuno-electron microscopy was used to study the efficiency of nitrogen
fixation in the presence of nZnO. Results showed a delay in the
onset of nodulation and the nitrogen-fixation process. No nitrogen
fixation was observed in nZnO-treated nodules at 7 dpi, whereas
immunogold label, indicative of activity of nitrogenase enzyme, was
detected in control nodules (Fig. S7a). At 14 dpi, nodules exposed to
nZnO showed activity of nitrogenase enzyme in the nitrogen fixative
zone (Fig. S7b–d). It was suggested that the defective outer membranes
of some bacteroids probably were repaired and able to perform effective
nitrogen fixation as the controlled. However, the total number of nitrogen
fixating bacteroids was lower in nZnO-treated nodules than that of
controls.