Fig. 11. Transmission electron microscopy (TEM) images of senescence cells in control and
nZnO treated nodules of Rhizobium leguminosarum bv. viciae 3841 at 14 dpi. (a) Highmagnification
view of bacteroids in control nodule. (b) High-magnification view of bacteroids
in nodule exposed to 250mg/L of nZnO. (c) High-magnification view of bacteroids in
nodule exposed to 750 mg/L of nZnO. The bacteroids in control cell showed an early stage
of senescence and the bacteroids were loosely associated with symbiosome membranes.
In nodule exposed to nZnO, the bacteroids, symbiosome membrane and cytoplasmic organelles
were greatly degraded. Scale bars: (a)–(c) = 0.5 μm. B: bacteroid.