Epigenetic control of early flowering in hyomethylated lines of flax (Linum usitatissimum) induced by 5-azacytidine

5-氮杂胞苷诱导的低甲基化亚麻系（Linum usitatissimum）早期开花的表观遗传控制

• 批准号: 2999-2006
• 负责人: Fieldes, MaryAnn
• 金额: $ 2.2万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=388686
• 关键词: Epigenetic; control; early; flowering; hyomethylated

The investigation of mechanisms that control plant growth and development is important because the growth characteristics of a plant determine its potential productivity. During the life cycle of a plant, the transitions between the different developmental phases are regulated by changes in gene expression. One of these transitions is prior to flowering, at the change from vegetative to reproductive growth. Although the physiology of this transition and the genes that ultimately determine the morphology of the flower are fairly well understood, less is known about the genes that initiate and regulate the transition. These genes determine flowering time (age). In the proposed research, early-flowering mutants of flax will be used to investigate the genes that control flowering time and the mechanisms that regulate changes in gene expression at the transition to flowering.  The early-flowering mutants were induced when seeds were treated with an agent that is known to demethylate DNA.  DNA methylation is thought to play a role in the processes that regulate gene activity during plant development.  In the early-flowering lines, the demethylation of the DNA, induced by the treatment, resulted in plants that flower early and are shorter than normal, with fewer leaves, thinner stems, and longer internodes. In each line, at least two independent genes control this early-flowering phenotype and it is thought that the demethylation of sites in the DNA associated with these genes has permanently altered their expression.  The proposed research will provide information about the genes and their roles in controlling flowering time, and also about the role of DNA methylation in regulating gene expression in plants. Early flowering is of agricultural interest because crop plants with short life spans can be planted late and still mature in time for harvest. The economic importance of flax lies in the linseed oil extracted from the seed, which has industrial uses. Canadian-grown flaxseed generates approximately $400 million/year in export revenue.

控制植物生长和发育的机制的研究是重要的，因为植物的生长特性决定了其潜在的生产力。在植物的生命周期中，不同发育阶段之间的转换是由基因表达的变化来调节的。这些转变之一是在开花之前，从营养生长到生殖生长的转变。虽然这种转变的生理学和最终决定花形态的基因已经相当清楚，但对启动和调节这种转变的基因知之甚少。这些基因决定开花时间（年龄）。在拟议的研究中，亚麻的早开花突变体将被用来研究控制开花时间的基因和在开花过渡期调节基因表达变化的机制。早开花突变体将被用来研究控制开花时间的基因和在开花过渡期调节基因表达变化的机制。当种子用一种已知能使DNA去甲基化的试剂处理时，会诱导开花突变体。DNA甲基化被认为在植物发育过程中调节基因活性的过程中起作用。在早花系中，由处理诱导的DNA去甲基化导致植物开花早，比正常情况下短，叶子少，茎细，节间长。在每一株系中，至少有两个独立的基因控制着这种早花表型，人们认为与这些基因相关的DNA位点的去甲基化永久地改变了它们的表达。拟议的研究将提供有关基因及其在控制开花时间中的作用的信息，以及DNA甲基化在调节植物基因表达中的作用。早开花在农业上是有意义的，因为寿命短的作物可以种植得很晚，但仍能及时成熟以供收获。亚麻的经济重要性在于从种子中提取的亚麻籽油，其具有工业用途。哥伦比亚种植的亚麻籽每年产生约4亿美元的出口收入。