Discovering the genetic drivers for host resource allocation between symbionts

植物与多种不同的有机体相互作用，其中许多有机体以植物组织为食以求生存。其中一些相互作用可能是互惠互利的，例如丛枝菌根真菌(AMF)，它们获得植物资源来促进它们的发育，同时也为它们的宿主提供养分。另一方面，植物也可以与寄生虫相互作用，例如植物寄生线虫。这些是微小的动物，依赖植物作为食物来源，不提供互惠的利益。植物可能会同时与这两种生物相互作用，因为超过一半的植物物种是植物寄生线虫的宿主，也是AMF物种的宿主。这两种共生体都必须通过操纵寄主植物内部的机制来竞争提供的有限数量的寄主资源(如糖和脂)，以将资源引导到自己身上。这种机制越来越多地被定义为单一共生体-宿主相互作用，但缺乏关于多个并发共生体如何影响资源分配机制的研究。这一新知识将对自然系统研究的相关性产生广泛影响。我对这一提议的初步工作提供了强有力的证据，证明宿主植物表达的基因可能有助于将资源转移到其根系统的某些区域，这是基于其与共生体的空间相互作用。有了这份奖学金，我将区分植物将其资源分配给有益和有害共生体的机制，以及两者共同的机制。这对未来在有害和有益的共生体之间调整资源分配的努力具有重要影响，这可能有可能提高作物产量和帮助粮食安全努力。通过结合一系列技术，我将操纵这些机制中涉及的选定数量的基因，以扰乱资源分配，并概述对共生体适应性的影响。我将把一种地上寄生虫整合到我的系统中，揭示导致寄生虫资源损失的常见机制，并更真实地代表自然生态系统。这将允许比较地上和地下寄生虫获取食物来源的机制。这一知识将为制定一套新的控制措施提供机会，同时考虑其对有益生物体的潜在影响。

Plants interact with a wide range of different organisms, many of which feed from plant tissues in order to survive. Some of these interactions can be mutually beneficial, such as arbuscular mycorrhizal fungi (AMF) that obtain plant resources to fuel their development whilst also contributing nutrients to their host. On the other hand, plants can also interact with parasites, such as plant-parasitic nematodes. These are microscopic animals that are dependent on plants as food sources and provide no reciprocal benefits. Plants will likely simultaneously interact with both of these organisms as over half of the plant species that are hosts to plant-parasitic nematodes are also host to an AMF species. Both symbionts must compete for the finite amount of host resources (such as sugars and lipids) that are on offer by manipulating mechanisms within the host plant to direct resources towards themselves. Such mechanisms are increasingly defined for single symbiont-host interactions, however there is a lack of research on how multiple, concurrent symbionts may impact resource allocation mechanisms. This new knowledge would have wide implications for the relevance of research in natural systems. My preliminary work for this proposal provides strong evidence that a host plant expresses genes that may facilitate the movement of resources to certain regions of its root system, based upon its spatial interactions with symbionts. With this Fellowship, I will differentiate the mechanisms by which a plant can allocate its resources to beneficial and detrimental symbionts, as well as those mechanisms that are common to both. This has important implications for future efforts to tailor the allocation of resources between detrimental and beneficial symbionts, which may have the potential to boost crop yields and aid food security efforts. By combining a range of techniques I will manipulate a select number of the genes involved in these mechanisms to disrupt resource allocation and outline the impacts on symbiont fitness. I will integrate an above-ground parasite into my system to reveal common mechanisms that result in resource losses to parasites and more faithfully represent natural ecosystems. This will allow comparisons between the mechanisms that above- and below-ground parasites utilise to gain access to their food sources. This knowledge will provide the opportunity for a new suite of control measures, whilst considering their potential impacts on beneficial organisms.