Figure 2.

UV-B induced cell death is delayed in the dewax mutant SAM. A, Mortality rate scored among the epidermal cell layer enriched TF mutant lines after UV-B exposure. B, Col-0, dewax, 35S::DEWAX, and hy5 seedlings were grown for 10 d and exposed to UV-B radiation. Images were taken 1 week after UV-B exposure to score the mortality rate. When exposed to UV-B, dewax mutant seedling showed more resilience compared to the Col-0 control. C, Mortality rate among the seedlings of Col-0, dewax, myb4, hy5, and 35S::DEWAX. Error bars represent the mean ± se of three biological replicates. In A and C, same lowercase letters indicate no statistical difference, while different letters denote within the group significant differences using ANOVA analysis followed by Uncorrected Fisher’s lsd multiple comparisons test (P < 0.01). D, Reconstructed side views of 4-week old dewax and Col-0 SAMs drawn from the confocal Z-series data. Plants were treated with UV-B for 2 min, and confocal images were acquired at the 2, 16, and 24 h time points. PI (red) was applied to stain the cell outlines and identify cell death in the growing SAM. Scale bars = 40 μm.