Figure 5 Overexpressing BrHIS4.A04 leads to increased chromatin H4 acetylation in Arabidopsis plants.
(A) H4 acetylation levels in five-week-old Col-0 andBrHIS4.A04OE plants with or without drought were determined by Western blotting using anti-H4 (acetyl K5+K8+K12+K16) antibody. The H4 protein level was used as an internal control. Under normal growth conditions, a higher level of H4 acetylation was observed in BrHIS4.A04OE plants. After drought treatment, the BrHIS4.A04 acetylation level increased dramatically in Col-0 plants; however, no increase was found inBrHIS4.A04OE plants. (B-F) The BrHIS4.A04 acetylation level at the ABI1, MYC2, FT , and FLC loci was determined by ChIP followed by RT-PCR analysis. Under normal growth conditions, the levels of H4 acetylation at all the tested loci were much higher in BrHIS4.A04OE plants compared to Col-0 plants. After drought treatment, the H4 acetylation levels of these genes increased dramatically in Col-0, but remained at about the same level as in theBrHIS4.A04O E plants grown under normal conditions. Error bars indicate ± standard error (SE) of the mean. Columns labeled with different letters are statistically different according to the Student’s t-test (P <0.05).