Fig. 5. RGA and RGL2 are key GA-response regulators of floral development. (A,B) Comparison of growth of ga1-3 plants lacking single (A) or pairs of (B) DELLA proteins at 48 days. Presence of wild-type gene (and functional protein) is indicated by +, presence of loss-of-function mutation (and lack of functional protein) is indicated by -. (C) ga1-3 plants lacking RGA and RGL2 initially produced sterile non-opening flowers (bottom right; SEM far right), then began to produce fertile open flowers (top right; SEM far right) when they were 50 days old. By contrast, ga1-3 plants lacking RGA alone (middle) never produced any fertile flowers.