Histone deacetylation is essential for temperature-induced hypocotyl elongation.

<p>A) Hypocotyl lengths of Col-0 plants grown in presence of different deacetylase inhibitors (at 10uM except for Trichostatin A (1uM) and a mock control at 23°C and 27°C. <i>p-values</i> for differences in hypocotyl elongation between 23°C and 27°C determined by a Student’s t-test N>15. B) Quantitative genetic interaction between genotype and histone deacetylase inhibition. The reaction norms for hypocotyl length in Col-0 (blue) and <i>pwr-2</i> (red) are shown in the presence (dashed lines, +I) or absence (solid lines) of Droxinostat. The drug x genotype interaction is shown. C) Reaction norms of the expression levels of <i>YUCCA8</i> in Col-0 and <i>pwr-2</i>. The drug x genotype interaction for Col-0 is shown. D) Hypocotyl lengths of <i>hda9</i> mutants at 22°C or 27°C. N>200. E) Recovery of the DNA fragments spanning the +1 nucleosomes at the <i>PIF4</i> and <i>YUC8</i> locus after immunoprecipitation of the nuclei with anti-H3K9ac antibodies through ChIP experiments. Error bars indicate standard error. <i>p-values</i>: ***<0.0001, **<0.001, *<0.05, ns = not significant.