Figure 9.

SlZFP2 binds directly to the promoters of ABA biosynthetic genes. A, Promoter enrichment of ABA biosynthetic genes by ChIP assay. Enrichments relative to input were determined by qPCR in triplicate. Nontrans, Nontransgenic siblings. B, In vitro binding of GST-SlZFP2 to the SlAO1 promoter using EMSA. The probes were amplified by PCR from genomic DNA using the same sets of primers used for the ChIP assay. C, Transient expression analysis of SlZFP2 binding to the promoters of ABA biosynthetic genes. The GUS reporters were driven by the promoters of the ABA biosynthetic genes NOT (1,856 bp), SIT (1,699 bp), FLC (1,959 bp), and SlAO1 (838 bp). After cotransformation with the internal control p35:LUC and the effector p35:SlZFP2 or pUC118 (empty vector control), GUS activity normalized to LUC activity (GUS/LUC) of each reporter was compared between the effector (p35S:SlZFP2) and the empty vector control (vector). Statistical significance was based on Student’s t test: *, P < 0.05; and **, P < 0.01. Data are means ± sd; n = 3.