Can Cyclin Dependent Kinase Activity be manipulated to control chromosome pairing and recombination in plants?

这个项目将解决一个重要的问题，这个问题阻碍了小麦野生近缘种遗传多样性的有效利用。驯化导致了一个显著的遗传瓶颈，结果是面包小麦的多样性远远低于其野生近缘种。能够与野生近缘种一起工作，从而将有益的性状引入商品小麦将是一项重大的科学成就，并将极大地改善育种者培育性能更高的小麦新品种的方式。一些野生近缘种适应在不同的气候条件下与国内小麦生长，或者它们具有对重要疾病的天然抗性和/或具有可能影响产量的其他重要特征。我们想要做的是找到一种方法，使我们能够有效地利用这种多样性，从而将这些有利的特性引入小麦。通过这样做，我们将使小麦育种者能够以可持续的方式改善小麦性能，提高产量，并引入抗病和耐旱性。是什么阻止了这些野生近亲被有效利用？理想情况下，野生亲缘种和小麦染色体在减数分裂期间应该对齐并有效地交换（重组），但这并没有有效地发生。没有重组，就没有机会将野生近缘种的遗传多样性引入小麦。一种叫做Ph1的遗传因子控制着这个过程。Ph1对小麦本身有积极作用，通过在减数分裂期间稳定小麦作为多倍体，但Ph1通过大量减少野生亲缘种和小麦染色体之间或这些染色体片段之间的重组来实现这一作用。Ph1甚至减少了来自小麦地方品种的染色体之间的重组。这使得在野生亲缘种减数分裂期间通过重组进行基因转移变得困难，而在地方品种中则效率低下。Ph1的缺失增强了重组，但它是非常有害的，因为它扰乱了多倍体基因组的稳定性。那么我们如何克服这个问题呢？在小麦及其杂交种中，Ph1调控重组。理解这一规则有助于深入了解这一过程。它将使我们了解如何根据特定需求改变和调整重组过程，从而使我们能够操纵它进行植物育种。在了解如何加强重组的过程中，该项目还将确定防止小麦本身染色体之间同源重组的方法，从而使其稳定为多倍体。我们的研究重点是在Ph1位点内发现的特定激酶样基因的作用。激酶通过将磷酸基团从ATP转移到目标蛋白质内的特定氨基酸来调节或控制其他蛋白质的功能。它们对包括ATP类似物在内的一系列化合物高度敏感，这些化合物已被开发用于生物医学目的，特别是癌症生物学和医学。因此，有一个巨大的资源可用于测试和鉴定化合物，将有效地调节这些相关的植物激酶。此外，我们最近在实验可适应的模式植物拟南芥中发现了Ph1相关激酶，这些激酶在所有物种（从植物到动物包括人类）的系统发育上都是保守的。在这个项目中，我们的目的是研究激酶活性在染色体配对和重组中的作用，以期开发化学介导的方法来调节减数分裂中的这些活性。这种化学工具不仅对小麦育种非常有用，而且对其他物种也有潜在的作用。

This project will address an important problem, which has hampered the efficient exploitation of the genetic diversity held within wild relatives of wheat. Domestication resulted in a significant genetic bottleneck with the result that breadwheat is much less diverse than its wild relatives. Being able to work with wild relatives so that beneficial characteristics can be introduced into commercial wheat will be a major scientific achievement and dramatically improve the way breeders can generate new varieties of wheat with increased performance.Some wild relatives are adapted to thrive under different climatic conditions to that of domestic wheat, or they carry natural resistance to important diseases and/or carry other important characteristics, which could influence yield. What we want to do is to develop approaches that will enable us to exploit this diversity effectively so as to introduce these favourable characteristics into wheat. In doing so we will be enable wheat breeders, amongst others, to improve wheat performance in a sustainable way, increase yield, and introduce disease resistance and drought tolerance.What stops these wild relatives being used efficiently? Ideally, the wild relative and the wheat chromosomes should align and efficiently exchange (recombine) during meiosis but this does not occur effectively. Without recombination, there isn't the opportunity to introduce the genetic diversity of wild relatives into wheat. A genetic element called Ph1 controls this process. Ph1 has a positive effect in wheat itself, by stabilizing wheat as a polyploid during meiosis, but Ph1 does this by substantially reducing recombination between wild relative and wheat chromosomes or between segments of these chromosomes. Ph1 even reduces recombination between chromosomes derived from wheat landraces where they are significantly diverged. This makes gene transfer by recombination during meiosis difficult in the case of wild relatives, or inefficient in the case of landraces. Deletion of Ph1 enhances recombination but is very deleterious because it perturbs stability of the polyploid genome.So how can we overcome this problem? In wheat and its hybrids, Ph1 regulates recombination. Understanding this regulation provides an insight into this process. It will provide us with an understanding of how the recombination process can be altered and tailored for specific needs, thus enabling us manipulate it for plant breeding. In understanding how to enhance recombination, the project will also identify approaches which prevent homoeologous recombination between chromosomes in wheat itself, and so stabilize it as a polyploid.Our research focuses on the role of particular kinase-like genes found within the Ph1 locus. Kinases regulate or control the function of other proteins by means of transferring a phosphate group from ATP to particular amino acids within the target protein. They are highly sensitive to a range of compounds, including ATP analogues, that have been developed for biomedical purposes particularly in cancer biology and medicine. Therefore, there is a tremendous resource available for testing and identifying compounds that would be efficacious in the modulation of these related plant kinases. Moreover, we have recently identified Ph1 related kinases in the experimentally amenable model plant, Arabidopsis, that are phylogenetically conserved across all species, from plants to animals including humans.In this project, we aim to investigate the role of kinase activity in chromosome pairing and recombination with the view to developing chemically mediated methods to modulate the activity of these in meiosis,. Such chemical tools would be tremendously useful in not only wheat breeding but potentially for other species as well.