Molecular mechanisms of virulence and avirulence in the Avr3a family of Phytophthora.

疫霉Avr3a家族毒力和无毒力的分子机制。

• 批准号: BB/I020470/1
• 负责人: Sophien Kamoun
• 金额: $ 30.04万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FI020470%2F1
• 关键词: Molecular; mechanisms; virulence; avirulence; Avr3a

The oomycetes are fungus-like eukaryotic microorganisms. Several species of the oomycetes are devastating pathogens that are of great importance to world agriculture and food security. In essence, this means that they destroy crops that are critical sources of food. The word 'Phytophthora', which is a genus with the oomycete lineage means 'plant destroyer'. Phytophthora species include the organism responsible for the Irish potato famine, Phytophthora infestans, which causes a disease commonly know as 'potato blight' or 'late blight' (it also causes tomato blight), as well as pepper blight (Phytophthora capsici) and soybean root rot (Phytophthora sojae). Recently, Phytophthora ramorum has gained considerable press in the UK as it is threatening iconic trees, such as oak. Phytophthora infestans remains the best-known and, arguably, the most important oomycete pathogen. It continues to cost modern agriculture billions of pounds annually and also impacts subsistence farming in developing countries. With potato now ranked the third most important crop in the world, P. infestans is an important biotic threat to global food security. Damage caused by other Phytophthora species is also severe, on a global scale. Our long-term objective is to understand how oomycetes, particularly Phytophthora, successfully infect plants and dissect the plant processes that are affected by these pathogens. It is now well established that, like other pathogens, Phytophthora species secrete a number of proteins, termed 'effectors', that modulate the immune response of plants and enable host colonization. Deciphering the biochemical activities of effectors is critical to understanding mechanisms of pathogenesis. Among these proteins, RxLR-type effectors, named after an amino acid sequence present in the protein, are targeted to the inside of plant cells. In this proposal, we focus on a particular group of RxLR effectors that is found in the Phytophthora species mentioned above. These are all members of the Avr3a family, as they share amino acid sequence homology to the Phytophthora infestans effector Avr3a. Building on preliminary data we have already obtained, we aim to define what conserved and divergent functions these proteins have in suppressing the plant immune system. Through host factors, members of this protein family can also initiate a programmed cell-death response in plants designed to limit pathogen growth. We also aim to understand some details of how early steps in this response occur, specifically how these effectors are detected by host cell factors. This study will help to establish functional connections between pathogen proteins and plant processes. Detailed knowledge of how the Avr3a family is able to manipulate certain aspects of plant immunity and be recognized by others will improve our understanding of the infection process and enable novel strategies for engineering resistance to Phytophthora pathogens.

卵菌是类似真菌的真核微生物。几种卵菌是毁灭性的病原体，对世界农业和粮食安全至关重要。从本质上讲，这意味着它们破坏了作为重要食物来源的农作物。 “Phytophthora”一词是卵菌谱系的一个属，意思是“植物破坏者”。疫霉属物种包括导致爱尔兰马铃薯饥荒的生物体致病疫霉（Phytophthora infestans），它会引起通常被称为“马铃薯疫病”或“晚疫病”（它也会引起番茄疫病）的疾病，以及辣椒疫病（Phytophthora capsici）和大豆根腐病（Phytophthora sojae）。最近，疫霉在英国受到了相当大的关注，因为它正在威胁着橡树等标志性树木。致病疫霉仍然是最著名的、可以说是最重要的卵菌病原体。它每年继续给现代农业造成数十亿英镑的损失，并影响发展中国家的自给农业。马铃薯现已成为世界第三重要作物，致病疫霉对全球粮食安全构成了重要的生物威胁。在全球范围内，其他疫霉属物种造成的损害也很严重。我们的长期目标是了解卵菌，特别是疫霉菌，如何成功感染植物并剖析受这些病原体影响的植物过程。现在已经确定，与其他病原体一样，疫霉属物种会分泌许多称为“效应物”的蛋白质，这些蛋白质可以调节植物的免疫反应并促进宿主定殖。破译效应子的生化活性对于理解发病机制至关重要。在这些蛋白质中，RxLR 型效应子以蛋白质中存在的氨基酸序列命名，靶向植物细胞内部。在本提案中，我们重点关注在上述疫霉属物种中发现的一组特定的 RxLR 效应子。这些都是 Avr3a 家族的成员，因为它们与致病疫霉效应子 Avr3a 具有氨基酸序列同源性。基于我们已经获得的初步数据，我们的目标是确定这些蛋白质在抑制植物免疫系统方面具有哪些保守和不同的功能。通过宿主因素，该蛋白质家族的成员还可以在植物中启动旨在限制病原体生长的程序性细胞死亡反应。我们还旨在了解这种反应的早期步骤如何发生的一些细节，特别是宿主细胞因子如何检测这些效应器。这项研究将有助于建立病原体蛋白和植物过程之间的功能联系。详细了解 Avr3a 家族如何能够操纵植物免疫的某些方面并被其他人识别，将提高我们对感染过程的理解，并为工程抗疫病病原体的新策略提供新的策略。

项目成果

Overcoming plant blindness in science, education, and society.

• DOI: 10.1002/ppp3.51
• 发表时间: 2019-07
• 期刊: Plants, people, planet
• 作者: Jose SB;Wu CH;Kamoun S
• 通讯作者: Kamoun S

Host-interactor screens of RXLR effectors reveal plant processes manipulated by Phytophthora

RXLR效应子的宿主相互作用筛选揭示了疫霉菌操纵的植物过程

• DOI: 10.5281/zenodo.3351297
• 发表时间: 2019
• 期刊: Zenodo
• 作者: Joe Win

Phytophthora infestans RXLR-WY Effector AVR3a Associates with Dynamin-Related Protein 2 Required for Endocytosis of the Plant Pattern Recognition Receptor FLS2.

• DOI: 10.1371/journal.pone.0137071
• 发表时间: 2015
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Chaparro-Garcia A;Schwizer S;Sklenar J;Yoshida K;Petre B;Bos JI;Schornack S;Jones AM;Bozkurt TO;Kamoun S
• 通讯作者: Kamoun S