Fig. 3. Functional divergence between BtKAI2 homologues.

a Germination responses of primary-dormant Arabidopsis seed homozygous for KAI2pro:GFP-BtKAI2 transgenes in the kai2-2 background. Germination values were determined 120 h after sowing. Extended germination curves are shown in Supplementary Fig. 7. Data are means ± SE, n = 3 independent seed batches, 75 seeds per batch. b Levels of KUF1 transcripts in KAI2pro:GFP-BtKAI2 seeds treated with 1 µM KAR₁ or KAR₂ for 96 h (see Methods). Expression was normalised to CACS reference transcripts and scaled to the value for mock-treated seed within each genotype. Data are means ± SE of n = 3 biological replicates. c Hypocotyl elongation responses of KAI2pro:GFP-BtKAI2 seedlings treated with KAR₁ or KAR₂. Data are means ± SE of n = 3 biological replicates, 12–18 seedlings per replicate. d Levels of DLK2 transcripts in 8-day-old KAI2pro:GFP-BtKAI2 seedlings treated with KAR₁ or KAR₂ for 8 h. Expression was normalised to CACS reference transcripts and scaled to the value for mock-treated seedlings within each genotype. Data are means ± SE of n = 3 biological replicates. Pairwise significant differences: *P < 0.05, **P < 0.01, ***P < 0.001; ns, P >0.05 (ANOVA). Source data are provided as a Source Data file.