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，这个问题阻碍了对野生近缘小麦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低于其野生近亲。能够与野生亲缘关系合作，从而将有益的特性引入商业小麦将是一项重大的科学成就，并将极大地改进育种者培育出性能更好的新小麦品种的方式。一些野生近缘小麦适应于与国内小麦不同的气候条件，或者它们具有对重要疾病的天然抗性和/或其他可能影响产量的重要特性。我们想要做的是开发方法，使我们能够有效地利用这种多样性，从而将这些有利的特征引入小麦。通过这样做，我们将使小麦育种者和其他人能够以可持续的方式改善小麦表现，增加产量，并引入抗病和抗旱能力。是什么阻止了这些野生近亲的有效利用？理想情况下，野生近亲和小麦的染色体应该在减数分裂过程中对齐并有效地交换(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的遗传多样性引入小麦。一种名为ph1的遗传元素控制着这一过程。PH1对小麦本身有积极的影响，在减数分裂过程中稳定了小麦的多倍体，但PH1通过显著减少野生亲缘染色体和小麦染色体之间的重组或这些染色体片段之间的重组来做到这一点。PH1甚至减少了来自小麦地方品种的染色体之间的重组，在这些地方，小麦地方品种的染色体明显分化。这使得在减数分裂过程中通过重组进行基因转移在野生近亲的情况下很困难，或者在地方品种的情况下效率低下。PH1的缺失促进了重组，但由于它扰乱了多倍体基因组的稳定性，所以它是非常有害的。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。了解这一规定有助于我们深入了解这一过程。它将让我们了解如何改变重组过程并为特定需求量身定做，从而使我们能够操纵它进行植物育种。为了了解如何加强重组，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，从而使其作为多倍体稳定下来。我们的研究重点是在PH1基因座中发现的特定的类似激酶的基因的作用。通过将一个磷酸基团从三磷酸腺苷转移到目标蛋白质中的特定氨基酸，激酶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，这些化合物是为生物医学目的而开发的，特别是在癌症生物学和医学中。因此，有大量的资源可用于测试和鉴定在调节这些相关植物激酶方面有效的化合物。此外，我们最近在实验上可服从的模式植物拟南芥中发现了与PH1相关的激酶，它们在从植物到动物包括人类的所有物种中都是系统发育保守的。在这个项目中，我们旨在研究激酶活性在染色体配对和重组中的作用，以期开发出化学介导的方法来调节这些活性在减数分裂中的活性。这样的化学工具不仅在小麦育种中非常有用，而且可能对其他物种也是如此。

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.