Figure 5.

GTL1 Is Expressed in the Abaxial Epidermis and Negatively Regulates SDD1 Expression.

(A) GUS activity in the abaxial epidermis of the first rosette leaf from 10-d-old seedlings harboring GTL1_pro:GUS was analyzed by histochemical staining. Arrow indicates a triangle-shaped meristemoid.

(B) GUS activity was not detected in the adaxial epidermis of fully expanded rosette leaves from 4-week-old transgenic plants harboring GTL1_pro:GUS.

(C) GTL1-GFP protein localization was analyzed in the leaf abaxial epidermis of 4-week-old transgenic plants harboring GTL1_pro:GTL1:GFP (#12-1) by fluorescence microscopy.

(D) Stomatal density was measured in 6-week-old wild-type (Col-0), gtl1-4 (empty vector control line), and GTL1_pro:GTL1:GFP complementation lines (#7-6 and #12-1) (mean ± se, n = 4; * indicates significant difference from the wild type at P < 0.05).

(E) GTL1-GFP protein expression in 6-week-old complementation lines and GFP protein expression in 6-week-old empty vector control plants were detected by immunoblot using anti-GFP antibody.

(F) and (G) RT-PCR analysis of SDD1, MPK3, MPK6, or UBC was performed on total RNA from fully expanded leaves of 8-week-old wild-type and gtl1 plants.