Figure 1.

CAX1 and CAX3 are expressed in guard cells. A, Expression levels of five CAX genes in guard cells (closed bar) compared with mesophyll cells (open bar) as assessed by microarray experiments (Yang et al., 2008). Expression levels were normalized to ACTIN2 (At4g33050). HPRP (At2g21140) and CBP (At4g33050) are shown as guard cell- and mesophyll cell-specific expression control (Jammes et al., 2009), respectively. B, RT-PCR analyses of CAX1 and CAX3. HPRP and CBP were amplified as cell-type specific marker genes.