{Reference Type}: Journal Article
{Title}: The PRR-EC complex and SWR1 chromatin remodeling complex function cooperatively to repress nighttime hypocotyl elongation by modulating PIF4 expression in Arabidopsis.
{Author}: Won JH;Park J;Lee HG;Shim S;Lee H;Oh E;Seo PJ;
{Journal}: Plant Commun
{Volume}: 0
{Issue}: 0
{Year}: 2024 May 29
{Factor}: 8.625
{DOI}: 10.1016/j.xplc.2024.100981
{Abstract}: The circadian clock entrained by environmental light-dark cycles enables plants to fine-tune diurnal growth and developmental responses. Here, we show that physical interactions among evening clock components, including PSEUDO-RESPONSE REGULATOR 5 (PRR5), TIMING OF CAB EXPRESSION 1 (TOC1), and the Evening Complex (EC) component EARLY FLOWERING 3 (ELF3), define a diurnal repressive chromatin structure specifically at the PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) locus in Arabidopsis. These three clock components act interdependently as well as independently to repress nighttime hypocotyl elongation, as hypocotyl elongation rate dramatically increased specifically at nighttime in the prr5-1 toc1-21 elf3-1 mutant, concomitantly with a substantial increase in PIF4 expression. Transcriptional repression of PIF4 by ELF3, PRR5, and TOC1 is mediated by the SWI2/SNF2-RELATED (SWR1) chromatin remodeling complex, which incorporates histone H2A.Z at the PIF4 locus, facilitating robust epigenetic suppression of PIF4 during the evening. Overall, these findings demonstrate that the PRR-EC-SWR1 complex represses hypocotyl elongation at night through a distinctive chromatin domain covering PIF4 chromatin.