Figure 4.

Acetylation State of Histones H3 and H4 Associated with the nfc102 Gene in Plants Expressing RNAi Knockdown Constructs against chc101 and mbd101 Contrasted with Their B73 Nontransgenic Siblings.

Leaf nuclei were prepared from UV-B–treated (UV-B) and control (no UV-B) plants. ChIP assays were done using antibodies specific for acetylated histone H3 ([A]; AcH3), acetylated H4 ([B]; AcH4), or total histone H4 ([C]; H4). The immunoprecipitates were analyzed for the presence of promoter and transcribed sequences of nfc102 and a transcribed sequence of a control gene that is not UV-B–regulated (th-like) by quantitative PCR. ChIP data were normalized to input DNA before immunoprecipitation. No signal was detected in control reactions (performed for each sample reaction reported above) incubated in the absence of any antibody. Quantitative RT-PCR analysis was also done to study transcript levels (nfc102 mRNA) in control and UV-B–treated plants (D). Fifty nanograms of cDNA after reverse transcription of RNA was used. All measurements were done at least in triplicate for each of the independent preparations. Error bars indicate se. Statistically significant differences between the UV-B and control treatments (Student's t test; P = 0.05) are labeled with asterisks.