Ammonium Inhibits Primary Root Growth by Reducing the Length of Meristem and Elongation Zone and Decreasing Elemental Expansion Rate in the Root Apex in Arabidopsis thaliana
Figure 3
Ammonium decreases apparent root meristem size and the number of dividing cells.
(A) Micrographs of PI-stained primary root tips at five days after treatment. Images are representative of 16 to 20 plants in four replicate experiments, treated as in Figure 1A. White arrowheads indicate the approximate position where cells begin to elongate noticeably. Bar = 50 µm. (B) Apparent root meristem length and (C) number of meristematic cortex cells (per file), seedlings treated as in Figure 1A. Bars plot means ± SD for 15 to 16 plants obtained in four replicate experiments. *** p<0.001. (D) Micrographs of the cell cycle reporter CycB1;1::GUS taken at the indicated days after transfer (DAT). Plants were treated as in Figure 1A. Bar = 50 µm. (E) The number of dividing cells as determined by counting the blue-green puncta in CycB1;1::GUS stained root tips. Bars plot means ± SD for 12 to 16 plants obtained in four replicate experiments. Different letters indicate significant differences at p<0.05.