The roles of DNA ligases in novel plant recombination pathways: from DNA repair to gene targeting.

DNA 连接酶在新型植物重组途径中的作用：从 DNA 修复到基因靶向。

• 批准号: BB/H012346/1
• 负责人: Christopher West
• 金额: $ 43.63万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FH012346%2F1
• 关键词: roles; DNA; ligases; novel; plant

DNA is essential for growth and reproduction. It contains the genetic information that is passed from one generation to the next, and encodes the factors needed for a cell to survive and divide. However, DNA in the cell is under constant attack from reactive molecules generated from within the cell or caused by environmental factors including carcinogens, UVB and soil pollutants such as heavy metals. DNA damage can have severe repercussions for the organism; a single DNA double strand break is sufficient to cause cell death if not accurately repaired. All organisms therefore require effective DNA repair mechanisms to counteract this damage. An essential step in nearly all DNA repair pathways is the re-joining of DNA ends, which is catalysed by a DNA ligase enzyme. Whilst yeast has two genes, higher organisms including mammals and plants have three DNA ligase genes, with specialised roles in maintaining the genome during DNA replication and repair. In this study we will determine the roles of the different DNA ligases in the higher plant Arabidopsis thaliana. Specifically, we determine the pathways in which each DNA ligase operates, and the importance for plant growth in adverse conditions. As part of this analysis we will characterise the role of each DNA ligase in recombination - the process whereby two DNA molecules are joined to make a new molecule. In DNA repair, recombination can occur by two processes; one method of repair uses an intact copy of the damaged DNA as a template for repair. This process is termed homologous recombination, and it involves the joining (recombining) of similar (homologous) sequences. The second process is largely independent of DNA sequence and is termed non-homologous end joining. It is important that we understand recombination processes in plants because DNA repair is required to allow growth of crop plants under conditions of adverse environmental stress, and failure of these pathways will both result in reduced crop yields and the accumulation of deleterious mutations in future generations. Given concerns over the impact of climate change on UK crop productivity, on it is now particularly important now that we understand how plants respond to environmental stresses. Understanding recombination in plants is also important for breeding new varieties of crop plants. Manipulation of DNA repair pathways will help develop crops that will tolerate altered climatic conditions and recent studies have also implicated homologous recombination in plant adaptation to give greater tolerances to pathogens. In addition, changing the activities of the plant recombination pathways will have effects on how we make transgenic plants. Transgenes usually integrate at random locations in the plant DNA. However, high levels of homologous recombination would allow us to target a transgene to a specific location in the genome, enabling more reliable expression and opening up the possibility of 'fine tuning' genes that are found naturally in the plant. This would lead to a second generation of transgenic plants that would address many of the criticisms of current methodologies.

DNA 对于生长和繁殖至关重要。它包含从一代传递到下一代的遗传信息，并编码细胞生存和分裂所需的因子。然而，细胞中的 DNA 不断受到细胞内产生的活性分子或环境因素（包括致癌物、UVB 和重金属等土壤污染物）的攻击。 DNA 损伤会对生物体产生严重影响；如果不进行精确修复，单个 DNA 双链断裂就足以导致细胞死亡。因此，所有生物体都需要有效的 DNA 修复机制来抵消这种损害。几乎所有 DNA 修复途径中的一个重要步骤是 DNA 末端的重新连接，这是由 DNA 连接酶催化的。酵母有两个基因，而包括哺乳动物和植物在内的高等生物体则有三个 DNA 连接酶基因，在 DNA 复制和修复过程中发挥着维持基因组的特殊作用。在本研究中，我们将确定不同 DNA 连接酶在高等植物拟南芥中的作用。具体来说，我们确定了每种 DNA 连接酶的运作途径，以及不利条件下植物生长的重要性。作为此分析的一部分，我们将描述每种 DNA 连接酶在重组（两个 DNA 分子连接形成新分子的过程）中的作用。在 DNA 修复中，重组可以通过两个过程发生：一种修复方法使用受损 DNA 的完整副本作为修复模板。这个过程称为同源重组，它涉及相似（同源）序列的连接（重组）。第二个过程很大程度上独立于 DNA 序列，称为非同源末端连接。我们了解植物中的重组过程非常重要，因为需要 DNA 修复才能使作物在不利的环境胁迫条件下生长，而这些途径的失败将导致作物产量下降和后代有害突变的积累。考虑到气候变化对英国作物生产力影响的担忧，现在我们了解植物如何应对环境压力变得尤为重要。了解植物重组对于培育农作物新品种也很重要。 DNA修复途径的操纵将有助于开发能够耐受气候条件改变的作物，最近的研究还表明植物适应过程中的同源重组可以赋​​予对病原体更大的耐受性。此外，改变植物重组途径的活性也会影响我们如何制作转基因植物。转基因通常整合在植物 DNA 中的随机位置。然而，高水平的同源重组将使我们能够将转基因定位到基因组中的特定位置，从而实现更可靠的表达，并开启“微调”植物中天然存在的基因的可能性。这将导致第二代转基因植物的出现，从而解决对当前方法学的许多批评。

项目成果

Arabidopsis TAF1 is an MRE11-interacting protein required for resistance to genotoxic stress and viability of the male gametophyte.

拟南芥 TAF1 是一种 MRE11 相互作用蛋白，是抵抗遗传毒性应激和雄性配子体活力所必需的。

• DOI: 10.1111/tpj.13020
• 发表时间: 2015-11
• 期刊: The Plant journal : for cell and molecular biology
• 作者: Waterworth WM;Drury GE;Blundell-Hunter G;West CE
• 通讯作者: West CE

Repairing breaks in the plant genome: the importance of keeping it together.

• DOI: 10.1111/j.1469-8137.2011.03926.x
• 发表时间: 2011-12
• 期刊: The New phytologist
• 作者: W. Waterworth;G. Drury;C. M. Bray;C. E. West