Ag's next frontier? Growing plants in space

July 17, 2015

Space may not be the final frontier for Anna-Lisa Paul and Robert Ferl; they want to grow plants there. Because, who knows, we may one day try to live on Mars, and to survive, we’ll have to grow our own food.

Thus far, experiments by the two pioneering scientists have proven so successful that, earlier this month, NASA recognized their research with one of its three awards in the category of the Most Compelling Results. Paul and Ferl have been conducting plants-in-space research for 20 years.

“It was indeed nice to receive the recognition from NASA,” said Paul, a research professor in the UF/IFAS Department of Horticultural Sciences. “The award recognizes our research approaches of using transgenic plants to serve as biological sensors of the space flight environment. This research is another step in moving our science forward in our exploration of how plants respond to this novel environment.”

Paul explained how all this research helps us on planet Earth.

“First, the more we can understand how plants respond to novel and extreme environments, the more prepared we are for understanding how plants will respond to the changing environments we are experiencing on Earth,” she said.

“Second, it gives the scientific community new insight into how plants sense and respond to external stimuli at a fundamental, molecular level. And last, what we learn helps inform our collective efforts to take our biology off the planet. When we leave Earth’s orbit, we will take plants with us,” added Ferl, a UF/IFAS horticultural sciences professor and director of the UF Interdisciplinary Center for Biotechnology Research.

NASA recognized Paul and Ferl for their work on three recent experiments.

During the experiments, NASA scientists sent plants to the International Space Station to test Paul and Ferl’s ideas about how plants sense changes in their environment, and then how they respond to those changes.

“One of the first things we found was that certain types of root-growth strategies that plants use on Earth that were always thought to require gravity for guidance actually do not require gravity at all, as we saw plants use those same strategies on the space station,” Paul said.

That result led to new hypotheses: In the absence of gravity, light plays a bigger role in guiding plant roots, and that researchers could get a clue as to what underlies those strategies by looking at the genes of the plants grown without gravity.

Their next experiment gave them some answers. They found that not only do plants grow in space by adjusting their basic metabolism, they saw a big difference in how various plant parts respond to space flight.

“This also gave us a clue about how roots may use light as a tool to guide growth when gravity is not available, and that is as an indication of which direction is ‘away’ from the leaves,” Paul said.

Then, she and Ferl wondered how the changes in gene expression in the different parts of the plant guided the proteins plants use to run the basic machinery important to growth and development. Was that different in space as well?

“We found that it was, and again, that each part of the plant had its own metabolic strategy for adjusting to an environment without gravity,” Ferl said.

The two scientists launched another experiment in January. “One of the most versatile tools we use in almost all of our space flight experiments are arabidopsis plants, engineered with glowing fluorescent proteins that can ‘report’ how they are responding to their environment,” he said. “We can follow how the plant is using those fluorescent proteins in adjusting to their new environment by using specialized cameras and microscopes.”

In the latest one, they used the Light Microscopy Module on the space station to see how these fluorescent reporters change in real time in microgravity.

“We have not fully analyzed our latest experiment, but we are learning new things about the specialized cells of the root that sense gravity on Earth,” Paul said.