Figure 9.

Stress and Plant Growth Phenotypes of agl22 Mutants.

Due to the early-flowering phenotype of both agl22 mutant alleles, drought stress was begun at 22 d after sowing.

(A) Rosette area (cm²) of Col-0 (light gray), agl22-3 (black), and agl22-4 (dark gray) plants at different soil water contents (n = 5). The asterisk indicates significant difference compared with the wild type at P < 0.05.

(B) Rate of water loss in agl22-3 and agl22-4 plants compared with the wild type averaged over 13 d of water withdrawal (n = 10). The asterisk indicates significant difference compared with the wild type at P < 0.05.

(C) Stomatal conductance (Gs) at different soil water contents in Co-0 (light gray), agl22-3 (black), and agl22-4 (dark gray) (n = 5). The asterisk indicates significant difference compared with the wild type at P < 0.05.

(D) Light-saturated carbon assimilation (Asat) at different soil water contents in Col-0 (light gray), agl22-3 (black), and agl22-4 (dark gray; n = 5). The asterisk indicates significant difference compared with the wild type at P < 0.05.

(E) Days to flowering in well-watered (light gray) and drought-stressed (black) plants (n = 10). Plants were grown under short-day conditions as described in Methods. At 5 weeks, plants were subjected to progressive drought stress. When 17% rSWC was reached, plants were rewatered and flowering time was recorded as days after sowing. Control plants were maintained well watered. The asterisk indicates significant difference compared with the wild type at P < 0.05.