Fig. 2.

ABA sensitivity of germination, after-ripening, and sucrose sensitivity of establishment. (A) After-ripening of WT (Ler) and prt6-4 seeds assayed on water agarose after 7 days. (B) Germination potential of seeds imbibed for 7 days on water-agarose media after increasing periods of cold, moist chilling. (C) Germination potential of seeds imbibed for 7 days on agarose media containing 1/2MS in the absence (black bars) and presence (white bars) of 100 μM GA₃. (D and E) Germination potential after 7 days of WT, mutant, and transgenic seeds assayed on 1/2MS media in the presence of exogenous ABA following 2 days of moist chilling. Seeds were stored for 2 months before assay. Respective WT and mutant seeds are: Col-0, prt1-1, prt6-1, prt6-2, ate1-2, ate2-1, abh1, ahg1, 2, 3 (3–5 and 36–39). Data points for ate2-1 are slightly obscured by those of prt1. Results obtained for ABI3OX, ABI5OX, and aip2 are presented in Fig. S2D. (F and G) Change in sensitivity of endosperm rupture (F) and testa rupture (G) to exogenous ABA, with time of dry storage of cold, chilled WT (Ler) and prt6-4 seeds, assayed on 1/2MS media and measured at 7 days following 2 days of moist chilling. (H) Sucrose sensitivity of establishment (greening of cotyledons) of WT, transgenic, and mutant seedlings grown on water-agarose supplemented with 1% (wt/vol) sucrose measured at 7 days, following 2 days of moist chilling. Dose–response curves are presented in Fig. S4. Data represent means ± SE of the mean.