Newswise — ITHACA, N.Y. – Plant pathogens can hitch rides on dust and remain viable, with the potential for traveling across the planet, according to a new Cornell University study – a finding with important implications for global food security and predicting future outbreaks.
The study is the first to provide computer modeling evidence to support the idea that massive dust storms can transport viable pathogenic spores across continents and oceans.
The Earth system model simulated a major dust storm, nicknamed “Godzilla,” that brought some 24 million tons of dust from North Africa across the Atlantic Ocean to the Caribbean and southeastern United States in the summer of 2022.
The researchers found that viable spores of the deadly fungal plant pathogen Fusarium oxysporum (F. oxy) could be transported across the ocean and were likely deposited across a range of regions that include agricultural production zones, most significantly in southeastern Louisiana, Mexico, Haiti and the Dominican Republic, with particularly high risk in Cuba.
“We found that this Godzilla dust event could have potentially brought over 13,000 viable live spores, which is not a lot, but it’s never been shown before, by any means, that viable soilborne pathogens could be transported trans-oceanically with dust,” said study co-author Kaitlin Gold, assistant professor of plant pathology at Cornell AgriTech.
The model included previous research of F. oxy viability showing that 99% of all spores are killed within three days of being airborne due to ultraviolet radiation exposure.
“For long distance transport, when we just look at total spores, including ones that maybe deactivated while they’re in the atmosphere, we see there are many that are traveling very long distances,” said Hannah Brodsky, the paper’s first author, who conducted the work as an undergraduate in the lab of Natalie Mahowald, the study’s senior author and professor of engineering.
Soil-adapted F. oxy is found on all six crop-producing continents and can infect more than 100 crops and other plants, leading to losses of up to 60% of crops and hundreds of millions of dollars in some areas.
Though F. oxy is soil adapted and not equipped to survive well when airborne, researchers have found that the pathogens attach to soil particles in dust clouds.
The study also included a literature search with more than 1,100 references for different species to create an interactive web map that showed variable spore concentrations in soils. This data improved the accuracy of the model’s results by an order of magnitude, compared with uniform distributions of spores used in early versions.
The researchers found that sub-Saharan Africa was a source for 53% of all viable spores and 14% of viable spores that travelled across the Atlantic.
“This is the region that should likely be targeted for addressing the disease,” Gold said.
The researchers note that the study is preliminary, with future work focused on gathering observational data for corroborating the model’s results – including creating remote sensing maps of dust storms and genomic comparisons of F. oxy between dust sources and areas of disease outbreaks.
The study was funded by NASA.
For additional information, see this Cornell Chronicle story.
Cornell University has dedicated television and audio studios available for media interviews.
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