Figure 5.

Transcriptional responses to ABA in sgt1 and hsp90.2 DN mutants and HSC70-1 OE lines and SnRK activities. A, Autoradiogram of an in-gel kinase assay performed with total extracts (top section) and immunoprecipitated OST1 (bottom section) prepared from Col-0 cell suspension cultures preincubated for 2 h with 0 or 10 nm radicicol and subsequently treated with/without 30 μm ABA for 10 min before harvest. Asterisk, black, and white circle correspond essentially to MPK6, SnRK2.2/3, and SnRK2.6 (OST1) kinase activities. B to D, cDNA was prepared from 10-d-old seedlings 3 h after a 10 μm ABA or mock treatment and its abundance measured by quantitative RT-PCR. Relative cDNA abundance of the ABA-responsive genes RD29A and RAB18 was expressed relative to ABA-treated Col control (B), relative to Col mock control (C), and as induction fold relative to mock control within each genotype (D). Actin8 (ACT8) and ROC3 expression was used to normalize the transcript levels. Three independent RT-PCR experiments were performed on three independent biological samples. The bars represent mean values from three independent experiments and error bars indicate sds. *, Significant differences compared to the wild type (Student’s t test, P < 0.05).