Figure 9.

Cell wall (CW) thickness of guard cells as measured from transmission electron micrographs of rosette leaves of WT, tgg1, tgg2 single and tgg1 tgg2 double mutants of Arabidopsis. Error bars represent the means ± SE (WT: n = 17), (tgg1: n = 17), (tgg2: n = 8), and tgg1 tgg2 (n = 20). Different letters (a and b) above the bars indicate significant differences in guard cell CW thickness between WT, tgg1, tgg2 and tgg1 tgg2 as determined by a Kruskal-Wallis test followed by a Dunn’s method for pairwise comparisons (p < 0.05).