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The regulation of plant-nematode parasitism

植物线虫寄生的调控

基本信息

批准号：
BB/R011311/1
负责人：
Sebastian Eves-Van Den Akker
金额：
$ 124.77万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FR011311%2F1
关键词：
regulation plant nematode parasitism

项目摘要

Summary: The regulation of plant-nematode parasitism.Plant-parasitic nematodes are a persistent threat to global food security. The most economically important species have the ability to transform plant cells into permanent and dedicated feeding sites. Plants and parasitic nematodes are locked in an "evolutionary arms race". At the front-line, are the parasite "effectors": molecules secreted into the host plant during infection. Plant-parasitic nematodes use hundreds of effectors to manipulate their host. Often individual effectors target a specific function in the host. The scientific community has focused on trying to understand and block these effector functions.A vulnerability of this approach is that for thousands of years plants have been deploying resistance genes to recognise effectors, and mount an immune response. This means that the parasites are under a strong evolutionary selection pressure to counteract this, developing a number of mechanisms to evade or negate effector recognition (sequence diversity, partitioning effectors in regions of the genome that mutate rapidly, functional redundancy, etc.). Practically, this means that targeting individual effectors to control the parasite is rarely highly successful, and unlikely to be robust. What we need is a series of new targets that have not been the focus of this kind of evolutionary selection pressure.This proposal is designed to deliver new targets by shifting the focus away from individual effectors to "high-level" functions: how is parasitism regulated? The idea is that if we can disrupt the process of parasitism regulation we can disrupt the functions of many effectors at the same time. Two recent breakthroughs in our understanding of parasitism regulation suggest that now is the right time to initiate this shift in focus.In 2016 I identified a regulatory genetic signature of nematode effectors. This signature unifies hundreds of otherwise unrelated effectors. This implies there is some nematode regulatory machinery that recognises this signature, and in so doing orchestrates this aspect of parasitism. I predict that if we could disrupt this "master-regulator", it would in turn disrupt hundreds of associated effectors. In a recent effort I have identified a candidate for such a regulator.The second breakthrough is the discovery that nematodes do not synthesise all effectors at the same time, suggesting that they may be delivered in waves that indicate a complex "parasitism programme" during infection. This sequential programme of effector production suggests that there will be a series of additional regulators that are activated at specific time-points. Disrupting any of these is likely to be severely detrimental to the parasite. Importantly, the plant immune system is "blind" to these master regulators. This means that they are unlikely to be protected by the same mechanisms that make targeting effectors so difficult. Together, this suggests that parasitism master regulators will be an attractive set of targets for control. In this proposal I will identify, validate, and disrupt these master-regulators.The fact that parasitic nematodes predictably execute a "parasitism programme" also gives us some insights into how they transform plant tissues. It suggests that the regulation of feeding site formation in the host is probably a multi stage process, and has the same or a very similar number of stages. This is a new insight into how this tissue is formed and presents an opportunity to understand the fundamental biology that underpins this process. In this proposal I will develop a system to measure changes in the host gene regulation and link these changes to progression through the nematode parasitism programme, ultimately building the foundation to understand this phenomenon.

摘要：植物线虫寄生的调控。植物寄生线虫是对全球粮食安全的持续威胁。经济上最重要的物种有能力将植物细胞转化为永久和专用的觅食场所。植物和寄生线虫被困在一场“进化军备竞赛”中。处于最前线的是寄生虫的“效应器”：在感染过程中分泌到宿主植物中的分子。植物寄生线虫使用数百个效应器来操纵它们的宿主。通常，单个效应器针对宿主中的特定功能。科学界一直致力于试图理解和阻止这些效应器的功能。这种方法的一个弱点是，数千年来，植物一直在利用抗性基因来识别效应器，并启动免疫反应。这意味着寄生虫面临着强大的进化选择压力来抵消这一点，形成了许多逃避或否定效应器识别的机制(序列多样性、在基因组快速突变的区域中分割效应器、功能冗余等)。实际上，这意味着以单个效应器为目标来控制寄生虫的做法很少是非常成功的，而且不太可能是强有力的。我们需要的是一系列新的目标，而这些目标并不是这种进化选择压力的焦点。这项提议旨在通过将重点从个体效应者转移到“高水平”功能来交付新的目标：如何监管寄生虫？我们的想法是，如果我们能够扰乱寄生调控的过程，我们就可以同时扰乱许多效应器的功能。最近我们对寄生调控的理解取得了两项突破，这表明现在是启动这一焦点转移的合适时机。2016年，我发现了线虫效应器的监管遗传特征。该签名统一了数百个原本不相关的效应器。这意味着有一些线虫监管机制识别这个签名，并在这样做的过程中协调寄生的这一方面。我预测，如果我们能够扰乱这一“主调控”，它将反过来扰乱数百个相关的效应器。在最近的一项工作中，我已经确定了这样一个调节器的候选者。第二个突破是发现线虫不会同时合成所有的效应器，这表明它们可能以波的形式传递，这表明在感染过程中有一个复杂的“寄生计划”。效应器生产的这一顺序计划表明，将会有一系列额外的调节器在特定的时间点被激活。破坏其中任何一种都可能对寄生虫造成严重损害。重要的是，植物免疫系统对这些主要调节器是“盲目的”。这意味着它们不太可能受到使瞄准效应器变得如此困难的相同机制的保护。总而言之，这表明寄生主监管者将是一组有吸引力的控制目标。在这项提案中，我将识别、验证和破坏这些主调控因子。寄生线虫可以预见地执行“寄生计划”，这一事实也给了我们一些关于它们如何转化植物组织的见解。这表明，寄主取食部位的形成可能是一个多阶段的过程，具有相同或非常相似的阶段数。这是对这种组织如何形成的新见解，并为理解支撑这一过程的基本生物学提供了机会。在这项提议中，我将开发一个系统来测量宿主基因调控的变化，并通过线虫寄生计划将这些变化与进展联系起来，最终为理解这一现象奠定基础。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Genome Expression Dynamics Reveal the Parasitism Regulatory Landscape of the Root-Knot Nematode Meloidogyne incognita and a Promoter Motif Associated with Effector Genes.

DOI：
10.3390/genes12050771
发表时间：
2021-05-18
期刊：
Genes
影响因子：
3.5
作者：
Da Rocha M;Bournaud C;Dazenière J;Thorpe P;Bailly-Bechet M;Pellegrin C;Péré A;Grynberg P;Perfus-Barbeoch L;Eves-van den Akker S;Danchin EGJ
通讯作者：
Danchin EGJ

STATAWAARS: a promoter motif associated with spatial expression in the major effector-producing tissues of the plant-parasitic nematode Bursaphelenchus xylophilus.