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对于生长和繁殖是必不可少的。它包含从一代传到下一代的遗传信息，并编码细胞生存和分裂所需的因素。然而，细胞内的DNA不断受到细胞内产生的活性分子的攻击，或者是由致癌物质、紫外线B和重金属等土壤污染物等环境因素引起的。DNA损伤可能会对生物体产生严重的影响；如果不能准确修复，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伤。在几乎所有的DNA修复途径中，关键的一步是DNA末端的重新连接，这是由DNA连接酶催化的。虽然酵母有两个基因，但包括哺乳动物和植物在内的高等生物有三个DNA连接酶基因，在DNA复制和修复过程中扮演着维护基因组的特殊角色。在这项研究中，我们将确定不同的DNA连接酶在高等植物拟南芥中的作用。具体地说，我们确定了每个DNA连接酶的作用途径，以及在不利条件下对植物生长的重要性。作为分析的一部分，我们将描述每个DNA连接酶在重组中的作用--两个DNA分子连接形成一个新分子的过程。在DNA修复中，重组可以通过两个过程发生；一种修复方法是使用受损DNA的完整副本作为修复模板。这个过程被称为同源重组，它涉及相似(同源)序列的连接(重组)。第二个过程在很大程度上独立于DNA序列，称为非同源末端连接。我们必须了解植物中的重组过程，因为DNA修复是作物在不利环境胁迫条件下生长所必需的，而这些途径的失败将导致作物产量下降和有害突变在后代中积累。鉴于人们对气候变化对英国作物生产力的影响的担忧，鉴于我们现在了解了植物如何应对环境压力，这一点现在尤其重要。了解植物中的重组对于培育作物新品种也很重要。操纵DNA修复途径将有助于培育耐受气候条件变化的作物，最近的研究也表明，同源重组在植物适应中具有更强的耐受性。此外，改变植物重组途径的活性将对我们制造转基因植物的方式产生影响。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于基因组中的特定位置，从而实现更可靠的表达，并为在植物中自然发现的基因进行微调开辟了可能性。这将导致第二代转基因植物的出现，这将解决许多对当前方法的批评。

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