While NASA and its partners prepare for long crewed flights, scientists at the University of Florida are studying a problem that could prevent astronauts from growing fresh food in space. The issue is plant diseases.
On October 13, the MVP-Plant-02 study was sent to the International Space Station (ISS). It will test how plants respond to a fungal pathogen - that is, a disease-causing agent - under microgravity, when the force of gravity is barely felt. Scientists want to understand whether the space environment changes plants' protective properties and whether it makes infections more severe.
The project is led by researchers Andrew Schuerger, Robert Ferl and Anna-Lisa Paul. They combined expertise in phytopathology (the science of plant diseases) and plant physiology. The experiment involves a small flowering Arabidopsis thaliana, a relative of mustard, and the fungus Golovinomyces cichoracearum, which causes powdery mildew.
The specialists will check whether the fungus develops more aggressively in weightlessness and how the plant's gene activity changes as the disease progresses. For this they will use the MVP platform, created by Redwire Space Technologies. It allows experiments at different gravity levels. Plants in microgravity will be compared with plants under Earth gravity on the station and with a control group on Earth, at the Kennedy Space Center. This way scientists can separate the effect of weightlessness from other factors of space growing.
The main innovation is that infection is carried out already in orbit. Previously, the pathogen was applied to plants before launch. For this, Redwire and the University of Florida developed the Conidia Application Device, which sprays fungal spores onto leaves in a closed system. "Since we grow plants in microgravity from seeds, all defense mechanisms are switched on or suppressed under the influence of weightlessness before the spores even reach the tissues," Schuerger explained. According to him, this is a much more accurate test than infecting seedlings on Earth before launch.
The team includes master's graduate Kylie Soltez. She helped assess the importance of the new approach and the role of the device. "The Plant-02 team created the first device for infecting plants with pathogens during spaceflight. It will allow astronauts to sterilely spray powdery mildew spores onto Arabidopsis leaves in a closed system," Soltez said.
During the mission, scientists will receive images of some of the modules with plants to monitor their development. But the final answer to the question of whether microgravity changes disease severity and gene function will come only from detailed analysis of the material after return to Earth. If it turns out that infection is more aggressive in weightlessness, these data will help develop preventive measures for future bases on the Moon and Mars. In addition, the experiment will show that complex experiments with plants and pathogens can be conducted on the ISS.