Figure 3

Effects of different concentrations of Al on nucleoli in root tip cells of Allium cepa var. agrogarum L. (Arrowhead shows silver-stained materials). a-b. Control cells. c. Small amounts of silver-stained materials in nucleus (0.5 μM Al, 24 h). d. Large amounts of silver-stained materials in nucleus with increasing Al concentration and prolonging treatment time (5 μM Al, 48 h). e-f. Silver-stained materials extruded from the nucleus into the cytoplasm (50 μM Al, 24 h). g-k. Showing the leaching materials located near the nucleus and more and more materials accumulated in the cytoplasm with prolonging the duration of treatment (50 μM Al, 48 h). l-n. Showing the materials enclosed the nucleus, and accumulated in the cytoplasm and occupied nearly the whole cytoplasm (50 μM Al, 72 h). o-p. In long cells, the silver-stained materials gathered at the cell ends (50 μM Al, 72 h) and large rod-like structures formed (50 μM Al, 72 h). Scale bar = 10 μm.