Fig. 4: MdABI5 binds directly to the promoter of MdNRT1.5.

a ChIP-PCR assays of the enrichment of nitrate gene promoters in 35S::MYC and 35S::MYC-MdABI5 transgenic apple calli. The 18S served as the loading control. b EMSA of the interaction analysis between MdABI5 and labeled DNA probes in the promoters of MdNRT1.2, MdNRT1.5, MdNRT1.8, MdNRT1.9, MdNRT2.4, and MdNRT2.5. c The interaction between MdABI5 protein and the MdNRT1.5 promoter in the EMSA. Mutation probes of pMdNRT1.5 had a mutated ABRE where CACGTA was replaced with ACAAAC. d YIH assay of MdABI5 bound to the MdNRT1.5 promoter in vitro. 10−1, 10−2, and 10−3 indicate that the yeast concentration was diluted 10, 100, and 1000 times, respectively. 3-AT stands for 3-Amino-1, 2, 4-triazole