Fig. 5.

Epidermal BRI1 activity promotes cell proliferation and cell expansion in the root meristem. (A,B) Relative length of meristematic zones. (C,D) Relative number of cortical cells. (E,F) Relative size of cortical cells (calculated as meristem length divided by the cortical-cell number). (A,C,E) Quantification of apical meristem. (B,D,F) Quantification of basal meristem. The relative measurements are given as the percentage of Col-0 plants. Seven-day-old seedlings were analyzed. Results are presented as mean±s.e.m. (G) qRT-PCR analysis demonstrating the expression level of CYCB1;1 and KNOLLE relative to RCH1, which represents ‘total meristematic cells’. All genes were first normalized to the endogenous control. (H) Representative confocal laser scanning microscope image showing the expression of CycB1;1-GFP.