Hutton Seminar Series: Tracking worldwide migrations, evolutionary relationships and re-emergence of Phytophthora infestans
Plant disease is a limiting factor in agricultural production worldwide and many emerging pests and pathogen have become more severe with trade and changing climate. Plant pathogens cause global losses estimated to be as high as $33 billion per year. One of the largest challenges we face in agriculture is to develop and deploy the appropriate technologies that will help reduce plant diseases and allow sustainable intensification of crop production. Phytophthora infestans, the causal agent of potato late blight, was responsible for the Irish potato famine. Historically, late blight of potato caused widespread famine in Ireland. The pathogen is still a threat to food security globally. In 2009, potato and tomato late blight epidemics in the US were the worst in modern history due to a “perfect storm” of widespread inoculum distribution from tomato transplants and conducive rainy weather events.
Dr Ristaino and her team have developed a surveillance and mapping system called USAblight.org to report disease outbreaks and send alerts to stakeholders. They have also identified and tracked the spread of historic P. infestans using multilocus genotyping and next generation sequencing, geospatial analytics, data mining and pathogen detection methods. The same unique multilocus genotype, named FAM-1, caused both US and European historic outbreaks. The FAM-1 lineage was present for over a 100 years, shared allelic diversity and grouped with the oldest specimens collected in Colombia, and formed a genetic group that was distinct from more recent aggressive lineages. Population genomics data from historic P. infestans also links ancestral lineages to P. andina in the Andes. Dr Ristaino's team is developing new knowledge and combining sensors, bioinformatics and geospatial surveillance tools to observe, contain and limit outbreaks by this important plant disease.
Dr Ristaino works on the population genetics of historical epidemics of the pathogen that caused the Irish faminePhytophthora infestans and studies the population structure and epidemiology of modern day late blight outbreaks. Her lab is interested in the impact of migration, recombination and hybridization on the evolution of Phytophthora species. Her work has tracked migrations of P. infestans from its ancestral home in the Andes to the US and Europe. She developed pioneering research techniques for use of 150-year-old historic herbarium specimens to track epidemics. She is also using datamining of archival literature to map outbreaks. Her recent work with collaborators has used next generation sequencing to study historical outbreaks. Her lab also manages the disease surveillance network called USABlight.org. This surveillance system records late blight outbreaks, sends disease alerts to growers, and provides decision support tools for managing disease. She also conducts Phytophthora and molecular diagnostics workshops globally in the developing world and has described new species of Phytophthora and developed taxonomic keys for identification.
Dr Ristaino was named a Jefferson Science Fellow with the US Department of State in 2012 and has worked on a range of emerging plant diseases that impact global food security with USAID. She serves on the advisory board of the Triangle Center for Evolutionary Medicine. She directs a new faculty cluster at NC State on “Emerging Plant Disease and Global Food Security” and has led the Triangle Global Food Security Initiative. She was awarded a Fulbright Research Scholar award in 2017 and is currently on sabbatical conducting research at the University of Catania in Sicily. Dr Ristaino’ research impacts the science of plant pathology, epidemiology, population genomics, food security and also impacts global science policy.
