Genome-wide characterization of cis-acting DNA targets of OsNF-YB1 in rice. Oryza sativa

OsNF-YB1 is a transcription factor that plays important roles during rice grain filling. OsNF-YB1 is specifically expressed in aleurone layer of developing endosperm and OsNF-YB1 RNAi lines showed retardation in grain filling and produced small grains with chalky endosperm as well as the altered starch quality. To reveal the transcriptional regulatory framework of OsNF-YB1, we determined OsNF-YB1 DNA binding targets using chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq). ChIP-Seq analysis detected 933 binding peaks distributed 743 neighbor genes. OsNF-YB1 directly regulates genes involved in nutrient transport including sugar and amino acids, and interestingly, different from the reported binding site of NF-Y complex, the GCC-box (a binding motif of ERF transcription factors) was enriched in the binding peaks of OsNF-YB1. Overall design: Examination of 8-12 days after fertilization (DAF) OsNF-YB1-GFP rice caryopsis coat (The starchy endosperm and embryo of caryopses were removed, and the remaining structure was termed the caryopsis coat) with GFP antibody and Input serves as control.