Chromatin-Dependent Repression of the Arabidopsis Floral Integrator Genes Involves Plant Specific PHD-Containing Proteins  . Issue 10 (3rd October 2014)

• Record Type: Journal Article
• Authors: López-González, Leticia; Mouriz, Alfonso; Narro-Diego, Laura; Bustos, Regla; Martínez-Zapater, José Miguel; Jarillo, Jose A.; Piñeiro, Manuel
• Is Part Of: The Plant Cell. Volume 26:Issue 10(2014)
• Page Start: 3922
• Page End: 3938
• Publication Date: 2014-10-03
• DOI: 10.1105/tpc.114.130781
• Languages: English
• ISSNs: 1040-4651

Abstract

Abstract : This work shows that the Arabidopsis homologs SHL and EBS play independent roles in the repression of flowering and are required to maintain an inactive chromatin configuration in floral integrator genes by preventing high levels of H3 acetylation. SHL and EBS are plant-specific proteins and could represent a fundamental difference in gene expression control between plants and other eukaryotes. Abstract: The interplay among histone modifications modulates the expression of master regulatory genes in development. Chromatin effector proteins bind histone modifications and translate the epigenetic status into gene expression patterns that control development. Here, we show that two Arabidopsis thaliana paralogs encoding plant-specific proteins with a plant homeodomain (PHD) motif, SHORT LIFE ( SHL ) and EARLY BOLTING IN SHORT DAYS ( EBS ), function in the chromatin-mediated repression of floral initiation and play independent roles in the control of genes regulating flowering. Previous results showed that repression of the floral integrator FLOWERING LOCUS T ( FT ) requires EBS . We establish that SHL is necessary to negatively regulate the expression of SUPPRESSOR OF OVEREXPRESSION OF CO1 ( SOC1 ), another floral integrator. SHL and EBS recognize di- and trimethylated histone H3 at lysine 4 and bind regulatory regions of SOC1 and FT, respectively. These PHD proteins maintain an inactive chromatin conformation in SOC1 and FT by preventing high levels of H3 acetylation, bind HISTONE DEACETYLASE6, and play a central role in regulating flowering time. SHL and EBS are widely conserved in plants but are absent in other eukaryotes, suggesting that the regulatory module mediated by these proteins could represent a distinct mechanism for gene expression control in plants.