ChIP Assay for Rice Transcription Factors

For the chromatin immunoprecipitation (ChIP) assay, the 35S:OsMYB102-MYC and 35S:OsABF4-MYC constructs in the pEarly Gate 203 binary vector (Earley et al., 2006 (link)) were transfected into rice protoplasts as previously described (Zhang et al., 2011 (link)). The protoplasts were then subjected to crosslinking for 20 min with 1% formaldehyde under vacuum. The chromatin complexes were isolated and sonicated as previously described (Saleh et al., 2008 (link)). An anti-Myc polyclonal antibody (Abcam) and Protein A agarose/salmon sperm DNA (Millipore) were used for immunoprecipitation. After reversing the crosslinking and protein digestion, the DNA was purified using a QIAquick PCR Purification kit (Qiagen). The primer sequences for each gene are listed in Supplementary Table S1.