bHLH3 directly binds to promoter sequences of <i>TAT1</i> and <i>DFR</i> in ChIP-PCR assay.

<p>(A) ChIP-PCR analysis of the <i>in vivo</i> binding of myc-bHLH3 to the promoter of <i>DFR</i>. Chromatin from wild type plants (CK) and the transgenic plants constitutively expressing myc-bHLH3 (myc-bHLH3) was immunoprecipitated without (−) or with anti-myc antibody (+). Levels of the <i>DFR</i> promoter sequence (a 267-bp fragment containing two G-box motifs (CACGTG)) in the indicated chromatin were quantified by quantitative real-time PCR assay. PCR-amplification of a 77-bp 3′-UTR fragment of <i>DFR</i> was used as a negative control. The experiment was repeated three biological times with similar results. Error bars represent SE (n = 3). (B) ChIP-PCR analysis of the <i>in vivo</i> binding of myc-bHLH3 to the promoter of <i>TAT1</i>. Levels of the <i>TAT1</i> promoter sequence (a 111-bp fragment containing one G-box motif) in the indicated chromatin were quantified by quantitative real-time PCR assay. PCR-amplification of a 82-bp 3′-UTR fragment of <i>TAT1</i> was used as a negative control. The experiment was repeated three biological times with similar results. Error bars represent SE (n = 3).