Seed dormancy cycling in Arabidopsis: chromatin remodelling and regulation of DOG1 in response to seasonal environmental signals. (26th December 2014)

• Record Type: Journal Article
• Authors: Footitt, Steven; Müller, Kerstin; Kermode, Allison R.; Finch‐Savage, William E.
• Is Part Of: Plant journal. Volume 81:Number 3(2015:Feb.)
• Page Start: 413
• Page End: 425
• Publication Date: 2014-12-26
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12735
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12735-abs-0001"> <title>Summary</title> <p>The involvement of chromatin remodelling in dormancy cycling in the soil seed bank (SSB) is poorly understood. Natural variation between the winter and summer annual Arabidopsis ecotypes Cvi and Bur was exploited to investigate the expression of genes involved in chromatin remodelling via histone 2B (H2B) ubiquitination/de‐ubiquitination and histone acetylation/deacetylation, the repressive histone methyl transferases <italic>CURLY LEAF</italic> (<italic>CLF</italic>) and <italic>SWINGER</italic> (<italic>SWN</italic>), and the gene silencing repressor <italic>ROS1</italic> (REPRESSOR OF SILENCING1) and promoter of silencing <italic>KYP/SUVH4</italic> (<italic>KRYPTONITE</italic>), during dormancy cycling in the SSB. <italic>ROS1</italic> expression was positively correlated with dormancy while the reverse was observed for <italic>CLF</italic> and <italic>KYP/SUVH4</italic>. We propose ROS1 dependent repression of silencing and a sequential requirement of CLF and KYP/SUVH4 dependent gene repression and silencing for the maintenance and suppression of dormancy during dormancy cycling. Seasonal expression of H2B modifying genes was correlated negatively with temperature and positively with <italic>DOG1</italic> expression, as were histone acetyltransferase genes, with histone deacetylases positively correlated with temperature. Changes in the histone marks H3K4me3 and H3K27me3 were seen on <italic>DOG1</italic> (<italic>DELAY OF GERMINATION1</italic>) in Cvi during dormancy cycling. H3K4me3 activating marks remained stable along <italic>DOG1</italic>. During relief of dormancy, H3K27me3 repressive marks slowly accumulated and accelerated on exposure to light completing dormancy loss. We propose that these marks on <italic>DOG1</italic> serve as a thermal sensing mechanism during dormancy cycling in preparation for light repression of dormancy. Overall, chromatin remodelling plays a vital role in temporal sensing through regulation of gene expression.</p> </abstract>