Rothamsted Research, Harpenden, AL5 2JQ, UK.
Genome. 2010 Nov;53(11):856-68. doi: 10.1139/G10-059.
This review addresses the mechanisms by which epigenetic variation modulates plant gene regulation and phenotype. In particular we explore the scope for harnessing such processes within the context of crop genetic improvement. We focus on the role of DNA methylation as an epigenetic mark that contributes to epiallelic diversity and modulation of gene regulation. We outline the prevalence and distribution of epigenetic marks in relation to eukaryote developmental processes, and in particular identify where this may be relevant to crop traits both in terms of specific developmental stages and in relation to physiological responses to environmental change. Recent whole genome surveys have identified specific characteristics of the distribution of DNA methylation within plant genomes. Together with greater understanding of the mode of action of different maintenance and de novo methyltransferases, this provides an opportunity to modulate DNA methylation status at specific loci as an intervention strategy in crop genetic improvement. We discuss alternative approaches that may be suitable for harnessing such induced epiallelic variation. Most of the discussion is associated with Brassica crops, which demonstrate considerable morphological plasticity, segmental chromosomal duplication, and polyploidy.
本文综述了表观遗传变异调控植物基因表达和表型的机制。特别是，我们探讨了在作物遗传改良背景下利用这些过程的可能性。我们重点关注 DNA 甲基化为表观遗传标记的作用，它有助于等位基因多样性和基因调控的调节。我们概述了表观遗传标记在真核生物发育过程中的普遍性和分布情况，并特别确定了在特定发育阶段以及对环境变化的生理反应方面，这与作物性状有何关联。最近的全基因组调查已经确定了植物基因组内 DNA 甲基化分布的特定特征。随着对不同维持和从头甲基转移酶作用模式的更好理解，这为在作物遗传改良中通过特定基因座的 DNA 甲基化状态调节作为干预策略提供了机会。我们讨论了可能适合利用这种诱导的等位基因变异的替代方法。大多数讨论都与芸薹属作物有关，这些作物表现出相当大的形态可塑性、片段染色体重复和多倍体。
