Epigenetic control of the plant male gametophyte and germline

和动物一样，植物也有一个生殖系统，它依赖于雄性和雌性生殖细胞（精子和卵子）的产生和受精过程。由于几乎所有主要作物都需要这种有性生殖系统来产生种子，因此了解植物生育力和生殖的发育生物学至关重要。在动物中，最近的研究表明，携带信息的短分子RNA（“小RNA”/sRNA）对雄性生殖细胞的发育至关重要，这是以前从未预料到的。因此，细胞中产生和加工这些RNA分子的途径非常重要。在植物中，现在迅速积累的证据表明，这些RNA分子通过控制基因的表达方式、染色体的组装方式和对寄生虫的防御，在调节植物的正常发育和健康方面发挥着重要作用。令人惊讶的是，sRNA途径在调节植物繁殖中的作用尚未得到研究--尽管有证据表明它们可能履行同样的重要功能。例如，在雄性生殖细胞（花粉）的形成过程中，许多基因的表达发生了重大变化，RNA丰度发生了周期性变化，染色体结构发生了巨大变化。此外，一种称为RNAi的生物技术（它依赖于这些RNA途径发挥作用）已被证明在植物配子体中有效。我们的建议将调查-第一次-这些RNA加工途径在植物雄配子体和种系（所有包含在花粉粒）的存在和功能。使用一系列新技术，我们将使用破坏这些途径的病毒蛋白质来确定扰乱其正常功能对花粉发育和生育力的影响。这也将使我们能够找到花粉中哪些基因可能受到小RNA的调控。我们将研究编码RNA加工途径各个部分的基因是否在组成花粉的不同细胞中活跃。使用新的测序策略（454），我们将尝试测序并鉴定配子体中的所有sRNA分子，这将立即告诉我们哪些基因可能参与该系统。最后，我们将建立实验来测试用于处理特定类别的小RNA（“microRNA”）的细胞系统是否具有功能。就效益而言，该项目将提供关于植物如何繁殖的宝贵信息，允许与动物繁殖进行有意义的比较，并产生新技术，使人们能够更好地了解植物生命周期中这一经济上重要的部分。

Like animals, plants have a reproductive system that relies on the production of male and female reproductive cells - sperms and eggs - and a fertilization process. As almost all major crops require this sexual reproduction system to produce seeds, the importance of understanding the developmental biology of plant fertility and reproduction is critical. In animals, much recent work has shown that short information-carrying molecules of RNA ('small RNAs'/sRNAs) are essential for the development of male reproductive cells, a role that was never previously anticipated. The pathways in cells that generate and process these RNA molecules are consequently of great importance. In plants, there is now rapidly accumulating evidence to show that these RNA molecules have essential roles in regulating normal development and health of the plant, through controlling how genes are expressed, the way chromosomes are assembled and defence against parasites. Surprisingly, the role of sRNA pathways in regulating the reproduction of plants has not been studied - even though evidence is available to suggest that they are likely to fulfil the same kinds of important functions. For example, in the formation of the male reproductive cells (pollen) it is well established that there is a major change in the expression of many genes, a cycle of RNA abundance, and dramatic changes in the architecture of the chromosomes. Further, one biotechnology technique called RNAi (which relies on theses RNA pathways to work) has been shown to be effective in plant gametophytes. Our proposal will investigate - for the first time - the presence and function of these RNA processing pathways in the plant male gametophyte and germline (all contained in the pollen grain). Using a range of new technologies, we will use viral proteins that disrupt these pathways to determine the effect of perturbing their normal function on the development and fertility of the pollen. This will also allow us to find which genes in pollen that may be regulated by small RNAs. We will investigate whether the genes that encode the various parts of the RNA processing pathways are active in the different cells that compose the pollen. Using a new sequencing strategy (454) we shall then attempt to sequence and identify all the sRNA molecules in the gametophyte, which will tell us immediately which genes are likely to be involved in this system. Finally we shall set up experiments to test whether a cellular system for processing a specific class of small RNA ('microRNA') is functional. In terms of benefits, this project will provide valuable information on how plants reproduce, allow meaningful comparisons to animal reproduction and generate new technology that will allow greater understanding of this economically important part of the plant life cycle.