PIRE: U.S.-East Africa Research and Education Partnership: Cassava mosaic disease - A paradigm for the evolution of insect-transmitted plant virus pathosystems

PIRE项目在美国和东非的科学家和学生之间建立了研究和培训伙伴关系，以研究植物DNA病毒如何随着时间的推移而变化。植物DNA病毒已成为威胁全球农作物的主要病原体。这些研究将侧重于木薯花叶病，这是非洲的地方病，严重限制了木薯的生产，木薯是整个非洲大陆的主要粮食作物。 由于非洲是世界上增长最快的地区之一，预计到2050年人口将翻一番，达到24亿，因此生产足够数量的优质营养食品是一项挑战。农业越来越成为一项全球性的事业，寻找粮食安全问题的解决方案将取决于研究伙伴关系，例如探索植物DNA病毒如何进化的基础科学以及是什么限制了它们随着时间的推移而适应的能力。这些基本知识可以被其他人用来制定合理的，持久的战略来控制这些重要的植物病原体。该项目依靠美国和非洲参与者的综合专业知识和资源，为培训美国学生发展科学技能和在全球社区工作提供了一个极好的框架，以帮助确保发展中国家和发达国家未来的安全。植物病毒的分子进化是通过病毒基因组成分的突变、重组和重配发生的，导致高度的变化。在复杂的病原-宿主系统中，病原的进化结果受到许多生态因素的影响，包括农业实践、昆虫媒介种群、作物与水库植物之间的相互作用以及气候。我们对病毒进化的大部分知识都是基于现场收集的样本，这些样本只能提供特定时间和地点的病毒多样性快照。为了研究植物DNA病毒的全部进化潜力以及限制其进化的瓶颈，我们提出了在严格控制的实验条件下对病毒遗传多样性，出现，持久性和传播的驱动因素进行全面分析。我们将专注于使用NexGen测序导致木薯花叶病的DNA病毒，以比较它们在营养和粉虱传播，混合感染以及作为水库宿主的野生植物中的多样性。我们将询问是否通过宿主植物的移动和/或昆虫媒介的传播是限制病毒多样性的瓶颈。我们的研究的进化潜力和因素，有助于木薯花叶病毒病是革命性的，因为它将提供一个全面的框架，检查病毒进化的关系，主机，昆虫载体和环境，使用作物和接种方法，准确地反映真实的世界条件。我们的综合方法还将作为研究病毒进化的模型，并将为其他对植物，动物和人类健康产生负面影响的昆虫传播病毒的控制策略的制定提供信息。博士后研究人员，研究生和本科生将由一个强大的国际研究团队指导，其中包括病毒种群遗传学，昆虫媒介传播和种群动态，病毒/媒介/植物相互作用和STEM教育方面的专家。研究的多学科性质将为学员提供实验室和实地研究以及生物信息学方面的经验。这将使他们成为全球参与的独立科学家，在一系列研究方法和环境中奠定坚实的基础，并在国际和多学科合作中获得第一手经验。

This PIRE project establishes a research and training partnership between scientists and students in the United States and East Africa to study how plant DNA viruses change over time. Plant DNA viruses have emerged as leading pathogens that threaten crops worldwide. These studies will focus on Cassava mosaic disease, which is endemic to Africa and severely limits the production of cassava, a major food crop across the continent. Because Africa is one of the fastest growing regions in the world, with a population projected to double to 2.4 billion people by 2050, producing sufficient quantities of high quality, nutritious food is a challenge there. Agriculture is increasingly a global enterprise and finding solutions to food security problems will depend on research partnerships such as this one that explores the basic science of how plant DNA viruses evolve and what limits their ability to adapt over time. Such fundamental knowledge can then be used by others to develop rational, durable strategies to control these important plant pathogens. The project, which relies on the combined expertise and resources of U.S. and African participants, provides an excellent framework for training U.S. students to develop their scientific skills and to work in a global community to help ensure the future security of the developing and developed world.Molecular evolution of plant viruses occurs through mutation, recombination and reassortment of viral genome components, resulting in a high degree of variation. In complex pathogen-host systems, the evolutionary outcomes are influenced by many ecological factors including agricultural practices, insect vector populations, interactions between crops and reservoir plants, and climate. Most of our knowledge of viral evolution is based on field-collected samples, which only provide snapshots of viral diversity at specific times and locations. To examine the full evolutionary potential of plant DNA viruses and the bottlenecks that constrain their evolution, we propose a comprehensive analysis of the drivers of viral genetic diversity, emergence, persistence and spread under tightly controlled experimental conditions. We will focus on the DNA viruses that cause Cassava mosaic disease using NexGen sequencing to compare their diversity during vegetative and whitefly transmission, in mixed infections, and in wild plants that serve as reservoir hosts. We will ask if movement through the host plant and/or transmission by insect vectors serve as bottlenecks that limit viral diversity. Our study of the evolutionary potential and factors that contribute to Cassava mosaic disease is transformative in that it will provide a comprehensive framework for examining viral evolution in relationship to the host, the insect vector and the environment using a crop and inoculation methods that accurately reflect real world conditions. Our integrated approach will also serve as a model for examining viral evolution and will inform the development of control strategies for other insect-transmitted viruses that negatively impact plant, animal and human health. Postdoctoral researchers, graduate students and undergraduates will be mentored by a strong international research team, which includes experts on viral population genetics, insect vector transmission and population dynamics, virus/vector/plant interactions, and STEM education. The multidisciplinary nature of the research will provide trainees experience in laboratory and field-based research as well as bioinformatics. This will prepare them to become globally engaged, independent scientists with a solid foundation in a range of research methodologies and environments and first-hand experience in international and multidisciplinary collaborations.