Anjali Iyer-Pascuzzi, Purdue University
Erin Sparks, University of Delaware

The production of healthy food is essential to sustaining human life during long-duration space flights and for long-term space station survival. In space, plants must adapt to a novel environment with different stimuli and constraints not seen on Earth. Understanding how plants respond and adapt to the unique pressures of the spaceflight environment is critical for growing food required to sustain human life during long-term space exploration.

On Earth, plant pathogens cause upwards of 20 – 40% global crop loss from disease. Microbes, including plant pathogens, have been isolated from the International Space Station (ISS), and thus disease loss also threatens crop production in space. If we are to sustain human space exploration for long durations, we must have the ability to grow and harvest edible crops without crop loss from disease. This will require knowledge of how the plant immune system responds to spaceflight, and how plant pathogen colonization and virulence is impacted by spaceflight conditions including microgravity. However, our current knowledge plant-microbe interactions in space is very limited.

In this proposal we investigate how the plant immune system adapts to spaceflight and simulated microgravity. We first ask how the tomato immune system adapts to spaceflight when grown in the newly developed Advanced Plant Habitat (APH) aboard the ISS. We use both wild type and immune-deficient tomatoes and elicit defense responses with a chemical elicitor. Next, we ask how tomato colonization by a fungal pathogen, Fusarium oxysporum, is altered by simulated
microgravity on Earth.

The goals of this work are twofold: 1) gain fundamental insights into how the activated plant immune system responds in space in a horticultural crop, 2) gain knowledge of the impact of simulated microgravity on plant colonization and disease development by a pathogenic fungus.