A Hypomethylated population of Brassica rapa for forward and reverse Epi-genetics

BMC Plant Biology

Research Article

Carlos Marcelino Rodriguez Lopez¹  Michael J Wilkinson¹  Stephen Amoah²  Sue J Welham²  Stephen J Powers²  Smita Kurup²  Clare J Hopkins³  Graham J King⁴ 

[1] Plant Research Centre, School of Agriculture, Food and Wine, Faculty of Sciences, University of Adelaide, Waite Campus, PMB1, 5064, Glen Osmond, SA, Australia;Rothamsted Research, AL5 2JQ, Harpenden, Herts, UK;Rothamsted Research, AL5 2JQ, Harpenden, Herts, UK;Department of Pathology, The University of Melbourne, 3010, Melbourne, VIC, Australia;Rothamsted Research, AL5 2JQ, Harpenden, Herts, UK;Southern Cross Plant Science, Southern Cross University, 2480, Lismore, NSW, Australia;

关键词: DNA methylation;    Hypomethylation;    Epigenetics;    Crop plants;    Brassica;    5-Azacytidine;   

DOI  :  10.1186/1471-2229-12-193

 received in 2012-01-10, accepted in 2012-10-09,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundEpigenetic marks superimposed on the DNA sequence of eukaryote chromosomes provide agility and plasticity in terms of modulating gene expression, ontology, and response to the environment. Modulating the methylation status of cytosine can generate epialleles, which have been detected and characterised at specific loci in several plant systems, and have the potential to generate novel and relatively stable phenotypes. There have been no systematic attempts to explore and utilise epiallelic variation, and so extend the range of phenotypes available for selection in crop improvement. We developed an approach for generating novel epialleles by perturbation of the DNA methylation status. 5- Azacytidine (5-AzaC) provides selective targeting of 5mCG, which in plants is associated with exonic DNA. Targeted chemical intervention using 5-AzaC has advantages over transgenic or mutant modulation of methyltransferases, allowing stochastic generation of epialleles across the genome.ResultsWe demonstrate the potential of stochastic chemically-induced hypomethylation to generate novel and valuable variation for crop improvement. Systematic analysis of dose–response to 5-AzaC in B. rapa guided generation of a selfed stochastically hypomethylated population, used for forward screening of several agronomic traits. Dose–response was sigmoidal for several traits, similar to that observed for chemical mutagens such as EMS. We demonstrated transgenerational inheritance of some phenotypes. BraRoAZ is a unique hypomethylated population of 1000 E2 sib lines. When compared to untreated controls, 5-Aza C-treated lines exhibited reduced immuno-staining of 5mC on pachytene chromosomes, and Methylation Sensitive Amplified Polymorphism (MSAP) profiles that were both divergent and more variable. There was coincident phenotypic variation among these lines for a range of seed yield and composition traits, including increased seed protein content and decreased oil content, as well as decreased erucic acid and corresponding increases in linoleic and/or palmitic acid. Each 5-AzaC-treated line represents a unique combination of hypomethylated epialleles.ConclusionsThe approach and populations developed are available for forward and reverse screening of epiallelic variation and subsequent functional and inheritance studies. The generation of stochastically hypomethylated populations has utility in epiallele discovery for a wide range of crop plants, and has considerable potential as an intervention strategy for crop improvement.

【 授权许可】

Unknown   
© Amoah et al.; licensee BioMed Central Ltd. 2012. 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/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.