This project establishes a research and training partnership between scientists in the U.S. and East Africa to study the evolution of plant DNA viruses, which have emerged as leading pathogens and now threaten crops worldwide. Africa?s future depends on increasing food production to feed its growing population. There has been dramatic growth in the investments by governments, nongovernmental organizations, international donors and the private sector to develop the scientific expertise and infrastructure necessary to find solutions to the problems that limit African agriculture. The Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub in Kenya and the Mikocheni Agricultural Research Institute (MARI) in Tanzania were created to solve problems facing African farmers and limiting food security. A U.S.-East Africa partnership represents an excellent international opportunity for research synergy and training of U.S. students and early career scientists. 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.
Intellectual Merit :
Molecular evolution of plant viruses occurs through mutation, recombination and reassortment of viral genome components, resulting in a high degree of variation. In complex pathosystems, 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. These studies will focus on Cassava mosaic disease (CMD), which is endemic to Africa, and as such rely on the combined expertise and resources of the U.S. and African participants. Our study 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.
Broader Impacts :Agriculture is increasingly a global enterprise, and it is essential that U.S. scientists work with their counterparts in other countries to better understand plant pathogens as well as their hosts and insect vectors. The proposed experiments will increase our understanding of how plant DNA viruses evolve and the functional constraints on their evolution. They represent an important step in the development of rational, durable control strategies for these important plant pathogens. Cassava is a major food crop in Africa, but its production is severely limitedby CMD. A better understanding of the factors that drive the evolution of the CMD viral complex can be used to prioritize the limited financial and human resources available to combat the disease and to improve the lives of smallholder farmers in Africa. All resulting sequence data and analyses will be available to the broader scientific community through our web-based sequence analysis environment (SNAP Workbench). A unique aspect will be opportunities to communicate with the general public via the NC Museum of Natural Science. Equally important, the proposal provides a framework for recruiting and training a group of diverse, globally-engaged plant scientists to work with researchers around the world to help secure the food and biomass needs of the future.