HSI2/VAL1 PHD-like domain promotes H3K27 trimethylation to repress the expression of seed maturation genes and complex transgenes in Arabidopsis seedlings

BMC Plant Biology

Research Article

Naichong Chen¹  Randy D Allen¹  Angelika I Reichert¹  Vijaykumar Veerappan² 

[1] Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, 73401, Ardmore, OK, USA;Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, 73401, Ardmore, OK, USA;Current address: Department of Biological Sciences, University of North Texas, 76203-5017, Denton, TX, USA;

关键词: HSI2;    VAL1;    AGL15;    DOG1;    Transgene silencing;    Seed-maturation;    DNA methylation;    Histone methylation;    H3K27me3;    5-aza-2′-deoxycytidine;   

DOI  :  10.1186/s12870-014-0293-4

 received in 2014-05-14, accepted in 2014-10-17,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 seedlings, expression of this LUC transgene and certain endogenous seed-maturation genes is constitutively enhanced. The parental reporter line (WTLUC) that was used for mutagenesis harbors two independent transgene loci, KanR and KanS. Both loci express luciferase whereas only the KanR locus confers resistance to kanamycin.ResultsHere we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both KanR and KanS loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2′-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural seed maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent.ConclusionsThese data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.

【 授权许可】

Unknown   
© Veerappan et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.