‘Little tornadoes’ around leaves can spread deadly plant pathogens | Top Vip News

A new study led by Cornell University is the first to analyze plant spore dispersal at its source, where raindrops shake flexible leaves to initially disperse pathogens.

When raindrops hit a leaf of a wheat plant infected with rust (a pathogenic spore that has decimated crops around the world), the leaf shakes, creating small eddies of air that disperse the spores, where they could end up infecting healthy plants.

A analysis of this effect using high-speed cameras, described in Scientific advancescould be a first step towards designing a strategy to help reduce the spread of pathogens (not only spores but also bacteria, oomycetes and viruses) from leaves.

By applying theoretical analyzes to the high-speed camera images, the researchers were able to predict the trajectory of the spores and how they are transported by a spinning motion created by the vibrating leaves. “It’s kind of a little tornado in the air,” said Sunghwan Jung, corresponding author of the paper and a professor at Cornell. Zixuan Wu, a doctoral student in Jung’s lab, is the first author of the paper.

For their analysis, the researchers borrowed techniques typically used to study geophysical flows, which are large-scale oceanic and atmospheric air currents, and scaled them down by a few orders of magnitude to understand and predict the eddies they found in the air around a bouncing leaf of wheat. .

“We describe the magnitudes of these kinds of spinning movements, and then when they will form and how the spores move, so that everything is predictable,” Jung said.

Due to restrictions on working with real live spores, the researchers used miniature hollow glass particles to mimic the spores. They used their methods to better understand how many spores can break off from a leaf, where they can go, and how they travel away from an infected plant. Ultimately, the study can inform future research that finds a way to prevent spores from infecting healthy plants at their source.

“We haven’t been able to find the solution yet,” Jung said. “But if we can somehow control these kinds of vortex structures around the leaf, then we can reduce the spread of spores to new plants.”