Pathways to neo-functionalization: the past and future of strigolactone signalling

激素信号通路在植物生长发育的调控中起着至关重要的作用。Strigolactones(SLS)和KAI2-Ligand(KL)是密切相关的激素信号，调节特定的发育方面，包括枝条分枝和种子萌发。在开花植物中，包括大多数农作物，SL和KL通过密切相关的信号通路来调节发育。在进化方面，SL信号似乎是通过复制KL信号通路而产生的。事实上，在非开花植物中，有证据表明SL和KL信号通路至少部分重叠。这就提出了一个非常有趣的问题，即开花植物中的信号通路是否真的是分开的，或者它们是否部分或完全重叠。本项目旨在评估开花植物中SL和KL信号通路相互分离的程度，并在分子水平上了解这种“特异性”是如何产生的。我们将检验的主要假设是，受体蛋白对SL和KL的感知是高度特异性的，但这些途径调节发育的机制非常相似，至少部分重叠。为了解决这个问题，该项目将把丰富的新获得的基因组数据与模式植物拟南芥的强大实验系统结合在一起。通过评估SL和KL信号如何在陆地植物5亿年的历史中进化，我们可以提出关于这些途径的特异性的假设，然后我们可以在拟南芥侧根发育的背景下进行测试。这个项目将使我们了解如何培育植物以增强或减少SL或KL的某些影响，以提高产量。总而言之，通过分析SL和KL信号的过去和现在，我们可以确定未来作物改良的可能性。

Hormonal signalling pathways are vitally important in the regulation of plant growth and development. Strigolactones (SLs) and 'KAI2-Ligand' (KL) are closely related hormonal signals that regulate specific aspects of development, including shoot branching and seed germination. In flowering plants, including most crop plants, SL and KL act through very closely related signalling pathways to regulate development. In evolutionary terms, SL signalling appears to have arisen by duplication of the KL signalling pathway. Indeed, in non-flowering plants, there is evidence that the SL and KL signalling pathways overlap at least partially. This raises very intriguing questions as to whether the signalling pathways in flowering plants are truly separate, or whether they partially or even fully overlap.This project aims to assess to what extent the SL and KL signalling pathways in flowering plants are separated from each other, and to understand at a molecular level how this 'specificity' arises. The main hypothesis we will test is that the perception of SL and KL by receptor proteins is highly specific, but that the mechanisms by which these pathways regulate development are very similar and at least partially overlapping. To address this question, the project will bring together a wealth newly available genomic data, with a powerful experimental system in the model plant Arabidopsis thaliana. By assessing how SL and KL signalling have evolved throughout the 500 million year history of land plants, we can formulate hypotheses regarding the specificity of these pathways, which we can then test in the context of Arabidopsis lateral root development. This project will allow us to understand how plants could be bred to enhance or diminish certain effects of SL or KL in order to improve yields. In summary, by analysing the past and present of SL and KL signalling, we can define possibilities for future crop improvement.