Journal Article

cis-Regulatory Elements and Chromatin State Coordinately Control Temporal and Spatial Expression of FLOWERING LOCUS T in Arabidopsis

Farrona, Sara, Albani, Maria C, Reimer, Julia J, Turck, Franziska, Adrian, Jessika, Coupland, George

2010

Overview

Flowering time of summer annual Arabidopsis thaliana accessions is largely determined by the timing of FLOWERING LOCUS T (FT) expression in the leaf vasculature. To understand the complex interplay between activating and repressive inputs controlling flowering through FT, cis-regulatory sequences of FT were identified in this study. A proximal and an ~5-kb upstream promoter region containing highly conserved sequence blocks were found to be essential for FT activation by CONSTANS (CO). Chromatin-associated protein complexes add another layer to FT regulation. In plants constitutively overexpressing CO, changes in chromatin status, such as a decrease in binding of LIKE HETEROCHROMATIN PROTEIN1 (LHP1) and increased acetylation of H3K9 and K14, were observed throughout the FT locus, although these changes appear to be a consequence of FT upregulation and not a prerequisite for activation. Binding of LHP1 was required to repress enhancer elements located between the CO-controlled regions. By contrast, the distal and proximal promoter sequences required for FT activation coincide with locally LHP1 and H3K27me3 depleted chromatin, indicating that chromatin status facilitates the accessibility of transcription factors to FT. Therefore, distant regulatory regions are required for FT transcription, reflecting the complexity of its control and differences in chromatin status delimit functionally important cis-regulatory regions.

• Publisher: American Society of Plant Biologists
• Subject: Arabidopsis / Arabidopsis - genetics / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Base Pairing / Base Pairing - genetics / Base Sequence / Chromatin / Chromatin - metabolism / Chromosomal Proteins, Non-Histone / Chromosomal Proteins, Non-Histone - metabolism / Chromosome Mapping / conserved sequences / DNA-Binding Proteins / DNA-Binding Proteins - metabolism / enhancer elements / Flowering / Gene expression regulation / Gene Expression Regulation, Plant / gene overexpression / Genes / Genetic Loci / Genetic Loci - genetics / genetics / heterochromatin / Histones / Histones - metabolism / Leaves / loci / Lysine / Lysine - metabolism / metabolism / Methylation / Models, Genetic / Molecular Sequence Data / Photoperiod / Phylogeny / Plant cells / Plants / Promoter regions / Promoter Regions, Genetic / Promoter Regions, Genetic - genetics / Protein Biosynthesis / summer / Time Factors / transcription factors / Transcription Factors - metabolism / Transcription, Genetic / Transcriptional Activation / Transcriptional Activation - genetics