Figure 4. Both HRB1 and PP7 are involved in the regulation of stomatal aperture.

(A) Stomatal aperture of 4-week-old Ws and hrb1 plants under 2 µmol/m²/s blue light supplemented with 25 µmol/m²/s red light for 2 hours. (B) and (C) are the fluence responses of the stomatal opening in 4-week-old Ws and hrb1 or 4-week-old Col and pp7 plants under blue light supplemented with 25 µmol/m²/s red light for 2 hours. Data presented are means plus or minus standard errors (n = 70). The stomatal aperture of hrb1 is significantly different from that of Ws at 0.33, 0.58, and 1.71 µmol/m²/s (P<0.0001, Student's two-tailed heteroscedastic t tests). The stomatal aperture of pp7 is significantly different from that of Col at 0.22, 1.15, and 4.93 µmol/m²/s (P<0.001).