Fig. 4. B2 and B3 RAFs cooperate in ABA-induced SnRK2 activation.

a Photographs of wild-type and mutant seedlings after 4 weeks of growth in the soil. Bar = 1 cm. b Water loss of 4-week-old wild-type and high-order mutants. Error bars, SEM (n = 5 biological replicates, each replicate has 5 or 6 individual seedlings). c Stomatal closure of 4-week-old wild type and mutants in response to ABA. Error bars, SEM (n = 59 or 60 individual stomates). d Photographs of seedlings after 10 days germination and growth on 1/2 MS medium containing different concentrations of ABA. The position of mutants in the image is shown in the gray box at the bottom-right corner. e Photographs of seedlings growing 10 days after transfer to 1/2 MS medium with or without 50 µM ABA. Bar = 1 cm. f In-gel kinase assay showing the activation of SnRK2s and RAFs in wild-type and different mutants with or without 15 min of ABA or mannitol treatment. Arrows indicate the OK¹⁰⁰ band observed in Col-0, snrk2-triple, and pyl112458 mutants. g The ABA-induced phosphorylation of Ser171 and Ser175 of SnRK2.6 in wild-type and the OK¹⁰⁰ high-order mutants. Arrows indicate the non-specific bands recognized by anti-pS171 and anti-pS175 antibodies. Images shown are representative of at least two independent experiments. Source data are provided in Source Data.