Fig. 4

PbABF.E.2 is an upstream factor of PbCOB.A.2. a The cis-elements bound by ABA-binding factor (ABF) and C2H2-type zinc finger protein (ZFP) were predicted from the PbCOB.A.1 and PbCOB.A.2 promoters. b Reporter and effectors. c The LUC activities in tobacco leaves over-expressing PbABF.E.2, PbABF.E.1, PbABF.D.2, and PbABF.B were evaluated using a dual-luciferase assay. OE-replicate 1 and 2 indicate the two independent experiments. Standard error was calculated from at least five replicates. Analysis of variance was calculated by Student’s t-test. Asterisk indicate P < 0.05. d EMSA assay showing the physical binding of PbABF.E.2 to the PbCOB.A.2 promoter. ‘–’ and ‘ + ’ indicate the absence and presence of the recombinant PbABF.E.2-His protein, biotin-labeled probe, biotin-labeled mutant, or cold probe, respectively. Cold probe concentrations were tenfold ( +) and 100-fold (+ +) of labeled probes