Figure 4.

SDH genes are highly expressed in guard cells. A, GUS expression in guard cells from Arabidopsis transgenic plants carrying a SDH1-1 promoter fusion. Histochemical localization of GUS activity is shown for leaves of 2-week-old seedlings grown under axenic conditions. The SDH1-1 promoter (788 bp) drives high expression in guard cells. Bar = 25 μm. B, Expression of complex II genes in mesophyll and guard cells. Data used to generate the digital northern blot were obtained using the Arabidopsis eFP browser at http://bar.utoronto.ca (Winter et al., 2007). For each gene, expression was normalized with respect to the median value across essentially all wild-type samples in the AtGenExpress tissue data set (Schmid et al., 2005).