Genome-wide characterization of cis-acting DNA targets of ZmbZIP22 in maize

A new factor binds to the 27-kD γ-zein gene promoter was identified through probe affinity purification and mass spectrometry analysis. This new factor belongs to bZIP type TF (hence named as ZmbZIP22). Chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq) analysis with two biological replicates was performed to determine the DNA binding targets of ZmbZIP22. ChIP-Seq analysis detected 1,550 DNA binding sites distributed over 514 genes. We identified ACAGCTCA as the most conserved ZmbZIP22 binding motif. We confirmed that ZmbZIP22 binds the 27-kD γ-zein gene promoter in vivo, and also identified additional direct targets of ZmbZIP22. Examination of 15 days after pollination (DAP) wild type maize endosperm in duplicate with ZmbZIP22 specific antibody and IgG serves as control.