Role of Polycomb-group genes in commitment to flowering in Arabidopsis

与动物不同的是，植物的身体计划在成年后不断形成，并可以随着环境的变化而变化。植物一生中发生的最重要的变化之一是切换到开花。虽然花和营养枝都是从枝尖(分生组织)的干细胞群发育而来，但它们与植物枝条的不同之处在于，它们通常是确定的，一旦形成雌性生殖器官就停止生长。在大多数植物中，从枝条到花的形成受到环境中日长和温度的控制。一旦发生切换，即使环境发生变化，它也非常稳定。这对于确保不形成花/枝中间体很重要(这些中间体不会有效地制造种子)。了解这种稳定的开花承诺是如何控制的，这一点很重要，例如，有助于我们控制何时何地开花。我们正在研究一组蛋白质，这些蛋白质对动物和植物都很重要，可以让细胞记住它们的身份，这样皮肤细胞就不会在我们有生之年变成肠道细胞(细胞身份的不适当变化被认为是许多癌症的基础)。出乎意料的是，我们最近由BBSRC资助的研究表明，当这些蛋白质(称为Polycomb)在花中缺失时，花/枝的中间产物就会形成。因此，我们认为，稳定地切换到开花可能部分是因为多梳蛋白确保促进新梢形成的基因在花中不被激活。此外，我们发现我们可以确定哪些基因被多梳蛋白关闭，因为在细胞核中包装基因的组蛋白蛋白发生了特征性的变化。我们在这个项目中的目标是使用这些技术来确定在开花期间Pc-G必须关闭哪些靶标，以使花发育稳定。

Unlike animals, the plant body plan is formed continuously during adult life and can change in response to environment. One of the most significant changes that occurs during the life of a plant is the switch to flowering. Although flowers and vegetative shoots both develop from groups of stem cells at the tips of shoots (meristems), they differ from plant shoots in that they are usually determinate and stop growing once the female reproductive organs are made. In most plants, the switch from shoot to flower formation is controlled environmentally by daylength and temperature. Once the switch happens, it is very stable even if the environment is changed. This is important in ensuring that flower/shoot intermediates are not formed (these would not make seed effectively). Understanding how this stable commitment to flowering is controlled is important, for example for helping us to control when and where flowering occurs. We are studying a group of proteins that are important in both animals and plants for giving cells a 'memory' of their identity, so that / for example / skin cells don't change into gut cells during our lifetime (inappropriate changes in cell identity are thought to underlie many cancers). Unexpectedly, our recent BBSRC funded research showed that when these proteins (called Polycomb) are missing in flowers, flower/shoot intermediates are formed. We think therefore that the stable switch to flowering may in part occur because Polycomb proteins make sure that genes promoting shoot formation are not activated in flowers. In addition, we found that we could identify which genes are switched off by Polycomb proteins as there are characteristic changes which occur to the histone proteins which package genes in the nucleus. Our aim in this project is to use these techniques to identify which targets have to be switched off by Pc-G during flowering in order to make flower development stable.