Fig. 5.

Test of genetic interaction of CRK5 with ABI2 involved in ABA signaling or with ABA2 involved in ABA biosynthesis. (A) ABI2 is genetically epistatic to CRK5. Seeds of wild-type Col-0, CRK5-overexpression line OE-1, ABI2-overexpression line ABI2OE and CRK5/ABI2-double-overexpression line OE1×ABI2OE were directly planted on the ABA-free (0 μM) or 0.8 μM-ABA-containing MS medium, and the growth status was recorded 10 d after stratification. The experiments were repeated three times with similar results. (B) Statistical analysis of absolute (top) and relative values (bottom) of root length of different genotypes described in (A). Relative values of the root length of each genotype grown on ABA-containing medium are normalized relative to the value of the corresponding genotype at 0 μM ABA, which is taken as 100%. Values are the mean±SE of three biological determinations, and different letters represent significant differences at P<0.05 (Duncan’s multiple range test). (C) Loss-of-function of ABA2 (aba2) does not affect ABA-hypersensitive response of the CRK5-overexpression line OE-2. Seeds of wild-type Col-0, aba2 mutant, CRK5-overexpression line OE-2 and CRK5-overexpression line OE2 in the aba2 mutant background (OE-2×aba2) were directly planted on the ABA-free (0 μM) or 0.5 μM-ABA-containing MS medium, and the growth status was recorded 10 d after stratification. The experiments were repeated three times with similar results. (D) Statistical analysis of absolute (top) and relative values (bottom) of root length of different genotypes described in (C). Relative values of the root length of each genotype grown on ABA-containing medium are normalized relative to the value of the corresponding genotype at 0 μM ABA, which is taken as 100%. Values are the mean±SE of three biological determinations, and different letters represent significant differences at P<0.05 (Duncan’s multiple range test).