Genome-wide meta-analysis of maize heterosis reveals the potential role of additive gene expression at pericentromeric loci

BMC Plant Biology

Research Article

Alexander Thiemann¹  Felix Seifert¹  Stefan Scholten²  Heike Pospisil³  Robert T Grant-Downton⁴  Tobias A Schrag⁵  Albrecht E Melchinger⁵  Matthias Frisch⁶  Junjie Fu⁷ 

[1] Biocenter Klein Flottbek, Developmental Biology and Biotechnology, University of Hamburg, 22609, Hamburg, Germany;Biocenter Klein Flottbek, Developmental Biology and Biotechnology, University of Hamburg, 22609, Hamburg, Germany;Institute for Plant Breeding, Seed Science and Population Genetics, Plant Breeding and Biotechnology, University of Hohenheim, 70599, Stuttgart, Germany;Department of Bioinformatics, Technical University of Applied Sciences Wildau, 15745, Wildau, Germany;Department of Plant Sciences, University of Oxford, OX1 3RB, Oxford, UK;Institute for Plant Breeding, Seed Science and Population Genetics, Applied Genetics and Plant Breeding, University of Hohenheim, 70599, Stuttgart, Germany;Institute of Agronomy and Plant Breeding II, Biometry and Population Genetics, Justus-Liebig University, 35392, Giessen, Germany;Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, 100081, Beijing, PR China;

关键词: Heterosis;    Maize;    QTL;    Grain yield;    Additive gene expression;    Haplotype;   

DOI  :  10.1186/1471-2229-14-88

 received in 2013-11-26, accepted in 2014-03-28,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe identification of QTL involved in heterosis formation is one approach to unravel the not yet fully understood genetic basis of heterosis - the improved agronomic performance of hybrid F1 plants compared to their inbred parents. The identification of candidate genes underlying a QTL is important both for developing markers and determining the molecular genetic basis of a trait, but remains difficult owing to the large number of genes often contained within individual QTL. To address this problem in heterosis analysis, we applied a meta-analysis strategy for grain yield (GY) of Zea mays L. as example, incorporating QTL-, hybrid field-, and parental gene expression data.ResultsFor the identification of genes underlying known heterotic QTL, we made use of tight associations between gene expression pattern and the trait of interest, identified by correlation analyses. Using this approach genes strongly associated with heterosis for GY were discovered to be clustered in pericentromeric regions of the complex maize genome. This suggests that expression differences of sequences in recombination-suppressed regions are important in the establishment of heterosis for GY in F1 hybrids and also in the conservation of heterosis for GY across genotypes. Importantly functional analysis of heterosis-associated genes from these genomic regions revealed over-representation of a number of functional classes, identifying key processes contributing to heterosis for GY. Based on the finding that the majority of the analyzed heterosis-associated genes were addtitively expressed, we propose a model referring to the influence of cis-regulatory variation on heterosis for GY by the compensation of fixed detrimental expression levels in parents.ConclusionsThe study highlights the utility of a meta-analysis approach that integrates phenotypic and multi-level molecular data to unravel complex traits in plants. It provides prospects for the identification of genes relevant for QTL, and also suggests a model for the potential role of additive expression in the formation and conservation of heterosis for GY via dominant, multigenic quantitative trait loci. Our findings contribute to a deeper understanding of the multifactorial phenomenon of heterosis, and thus to the breeding of new high yielding varieties.

【 授权许可】

Unknown   
© Thiemann 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/2.0), 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.