The Contribution of Phytophthora effectors to host range and non-host resistance

疫霉效应子对寄主范围和非寄主抗性的贡献

• 批准号: BB/K018183/1
• 负责人: Paul Birch
• 金额: $ 34.49万
• 依托单位: University of Dundee
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FK018183%2F1
• 关键词: Contribution; Phytophthora; effectors; host; range

An increasing world population and impacts of climate change place ever-greater demands on the world food supply. A major constraint to global food security is crop loss due to plant pests and diseases. With the increasing stringency of conditions under which chemicals are approved for agriculture, the choice of effective fungicides and pesticides will become more limited in the near future. Furthermore, as introgressed host resistance genes are rapidly defeated by pathogens and pests in the field, there is an urgent need to explore sources of disease and pest resistance that are durable and will provide long term food security.Plants face a constant barrage of pest and microbial threats and defend themselves by employing at least two layers of inducible defence responses. The first layer involves recognition of Pathogen-Associated-Molecular-Patterns (PAMPs) by cell surface pattern recognition receptors (PRRs) to mount PAMP-triggered immunity (PTI). Successful (adapted) pathogens secrete and deliver molecules, effectors, inside host cells to suppress these defences. The second defence layer involves recognition of effectors by immune receptors, or NB-LRR proteins, to evoke effector-triggered immunity (ETI). This recognition is often based on detection of changes by NB-LRRs in the conformational/biochemical state of host proteins that are targeted by effectors. Most plants are resistant to most pathogens, which is termed non-host resistance (NHR). By definition this is effective against all genetic variants of a pathogen species, and thus durable. Effector recognition by NB-LRR proteins has been proposed to be a major determinant of NHR in plant species that are closely related to the pathogens' natural hosts. In contrast, evidence exists that inducible NHR in plant species that are distantly related to the pathogen's natural host(s) is the result of the inability of effectors to appropriately target plant proteins and suppress immunity. Recent progress in the identification of plant pathogen effectors, and their targets, has opened new avenues to investigate the contributions of these proteins to determining non-host resistance.This proposal aims to generate a key understanding of the role of effectors, their targets, and NB-LRR proteins in non-host resistance in the Solanaceae. The Solanaceae include economically important food crops, such as pepper, tomato, and potato, the latter being the world's fourth largest food crop, and the second largest in Europe after wheat. We will exploit effector sets from 2 important solanaceous pathogens with differing host ranges: the oomycetes Phytophthora infestans (infects potato and tomato but not pepper) and P. capsici (infects pepper and tomato but not potato). We will assess the contribution of Phytophthora effectors to defining host range. Our key objectives are to (i) assess whether effectors trigger NB-LRR-mediated immunity in non-host solanaceous plants, and (ii) whether inducible NHR in Arabidopsis, constitutes a failure of effectors to modify intended targets and thus suppress PTI. We will exploit the genome sequences of potato, tomato, N. benthamiana, N. sylvestris and pepper to identify targets for P. infestans and P. capsici effectors. We will then be able to investigate their role in mediating effector recognition in non-host solanaceous plants.The proposed work will shed light on the contribution of NB-LRRs, and the effector targets they monitor, to NHR within solanaceous crops. We will establish an essential platform that determines the molecular basis of NHR, identifies the critical effectors that activate NHR and paves the way to targeted searches for associated genes. Moreover, we will identify Arabidopsis PTI regulatory components, insensitive to effector activity, that can be deployed in Solanaceous crops. This approach will build a highly durable barrier to infection.

世界人口的增加和气候变化的影响对世界粮食供应提出了越来越高的要求。全球粮食安全的一个主要制约因素是植物病虫害造成的农作物损失。随着批准用于农业的化学品的条件越来越严格，在不久的将来，有效的杀菌剂和杀虫剂的选择将变得更加有限。此外，由于渗入的宿主抗性基因在田间被病原体和害虫迅速击败，迫切需要探索持久的病虫害抗性来源，以提供长期的粮食安全。植物面临着持续不断的害虫和害虫攻击。微生物威胁并通过采用至少两层诱导防御反应来保护自己。第一层涉及细胞表面模式识别受体 (PRR) 对病原体相关分子模式 (PAMP) 的识别，以启动 PAMP 触发的免疫 (PTI)。成功的（适应的）病原体会在宿主细胞内分泌和传递分子、效应物来抑制这些防御。第二个防御层涉及免疫受体或 NB-LRR 蛋白对效应器的识别，以激发效应器触发的免疫 (ETI)。这种识别通常基于 NB-LRR 检测效应子靶向的宿主蛋白的构象/生化状态的变化。大多数植物对大多数病原体都具有抗性，这被称为非宿主抗性（NHR）。根据定义，这对病原体物种的所有遗传变异都有效，因此是持久的。 NB-LRR 蛋白的效应器识别被认为是与病原体天然宿主密切相关的植物物种中 NHR 的主要决定因素。相比之下，有证据表明，与病原体天然宿主关系较远的植物物种中的诱导型 NHR 是效应器无法适当靶向植物蛋白并抑制免疫的结果。在识别植物病原体效应子及其靶标方面的最新进展，为研究这些蛋白质对确定非宿主抗性的贡献开辟了新的途径。该提案旨在对效应子、其靶标的作用和作用产生关键的理解。茄科非宿主抗性中的 NB-LRR 蛋白。茄科包括经济上重要的粮食作物，如胡椒、番茄和马铃薯，后者是世界第四大粮食作物，在欧洲仅次于小麦。我们将利用两种具有不同宿主范围的重要茄科病原体的效应子集：卵菌致病疫霉（感染马铃薯和番茄，但不感染辣椒）和辣椒疫病菌（感染辣椒和番茄，但不感染马铃薯）。我们将评估疫霉效应子对确定宿主范围的贡献。我们的主要目标是（i）评估效应器是否在非宿主茄科植物中触发 NB-LRR 介导的免疫，以及（ii）拟南芥中的诱导型 NHR 是否会导致效应器无法修改预期目标并从而抑制 PTI。我们将利用马铃薯、番茄、本塞姆氏猪笼草、森林猪笼草和辣椒的基因组序列来识别致病疫霉和辣椒疫霉效应子的靶标。然后，我们将能够研究它们在非宿主茄科植物中介导效应器识别中的作用。拟议的工作将阐明 NB-LRR 及其监测的效应器目标对茄科作物内 NHR 的贡献。我们将建立一个重要的平台，确定 NHR 的分子基础，识别激活 NHR 的关键效应子，并为有针对性地搜索相关基因铺平道路。此外，我们将鉴定拟南芥 PTI 调节成分，对效应子活动不敏感，可应用于茄科作物。这种方法将建立高度持久的感染屏障。

项目成果

All Roads Lead to Susceptibility: The Many Modes of Action of Fungal and Oomycete Intracellular Effectors.

• DOI: 10.1016/j.xplc.2020.100050
• 发表时间: 2020-07-13
• 期刊: Plant communications
• 影响因子: 10.5
• 作者: He Q;McLellan H;Boevink PC;Birch PRJ
• 通讯作者: Birch PRJ

Plant pathogen effector utilizes host susceptibility factor NRL1 to degrade the immune regulator SWAP70.

• DOI: 10.1073/pnas.1808585115
• 发表时间: 2018-08-14
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1
• 作者: He Q;Naqvi S;McLellan H;Boevink PC;Champouret N;Hein I;Birch PRJ
• 通讯作者: Birch PRJ

A Phytophthora infestans RXLR effector targets plant PP1c isoforms that promote late blight disease.

• DOI: 10.1038/ncomms10311
• 发表时间: 2016-01-29
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Boevink PC;Wang X;McLellan H;He Q;Naqvi S;Armstrong MR;Zhang W;Hein I;Gilroy EM;Tian Z;Birch PRJ
• 通讯作者: Birch PRJ