Pathogens and germs aren't just harmful to humans and animals; they can also wreak havoc on various types of plants. One particularly problematic pathogenic fungus for plants is known as rust. Although it's not the same as the rust found on metals, it shares a similar bright red, orange, yellow, and brown color that can detract from the appearance of decorative plants. More importantly, it can devastate important crops like wheat and barley.
Rust, like COVID-19, is airborne and spreads to healthy plants through tiny particles called spores. Understanding how these spores move is crucial for developing better methods to protect plants. A study published in the journal Science Advances on January 31 utilized high-speed cameras to analyze the dispersion of plant spores. The study revealed how small 'tornadoes' distribute pathogens from infected plants to healthy ones.
When a raindrop strikes a leaf infected with rust, the leaf flutters and creates swirling vortices of air that carry the spores. Similar to virus particles in a sneeze or cough, these spores can then infect nearby healthy plants.
The study, conducted by a team from Cornell University, used high-speed cameras to examine this process. This research could lead to the development of strategies to reduce the spread of pathogens from viruses, bacteria, and fungi from plant leaves.
The footage enabled the team to predict the path of the spores and how they are transported by the swirling vortex created by the leaves. The team employed techniques typically used to study large-scale atmospheric air currents like the jet stream, scaled down to understand and predict the air movements around a bouncing wheat leaf.
"It's like a miniature tornado in the air," explained study co-author and Cornell University biophysicist Sunghwan Jung. "We quantified the magnitudes of these swirling motions, identified when they form, and how spores move around, making everything predictable."
To mimic actual spores, the team used miniature hollow glass particles due to restrictions on working with live spores. This approach allowed them to estimate how many spores might detach from a leaf, their potential flight direction, and how they disperse from an infected plant.
The team anticipates that the data from this study could lead to the development of new methods to prevent spores from infecting healthy plants by targeting the source of spore dispersal.
"While we haven't found a solution yet," Jung stated, "if we can somehow control these vortex structures around the leaf, we may be able to reduce the spread of spores to new plants."