Plants in Space | College of Agriculture and Life Sciences

Space. You may have heard it’s the final frontier, but for NC State plant scientists, it’s the next frontier. Last June, plant biology experiments prepared by NC State professor Marcela Rojas-Pierce were shot into space at more than 176,000 miles per hour while aboard SpaceX’s Dragon Spacecraft. Their destination: the International Space Station where an on-board astronaut crew carried out protocols developed by these researchers. This important plant research will help us better understand how plants grow in space and back here on Earth.

On today’s episode of Farms, Food and You, we talk with Professor Marcela Rojas-Pierce and learn more about this out of this world experiment and what it means for the future of agriculture practices at home and beyond our atmosphere.

The roots of this experiment came when NASA sent out a notice requesting research experiments for the International Space Station. Rojas-Pierce answered the call.


So this came from an experiment that, or a project that we had been growing in the lab before we are studying how plants respond to gravity. And as part of that study, we were characterizing a plant that has abnormal response to gravity. So even on earth, um, it germinates and it doesn’t grow up, you know, there was, um, you know, against gravity, it just kind of grows everywhere. Um, and it gave us an opportunity to kind of understand how the phenotype of these plants, that is the way that this plant was abnormal, could affect its growth in space. And so it was a great opportunity to develop a new question where we would ask, um, how does microgravity affect these particular mutants, and how it would affect a specific cellular component in plant cells. And so, um, there was a call by NASA for experiments to be running the ISS and, and we submitted an application and, and was funded. So that’s how we, that’s how we got started.


Rojas-Pierce sent two Arabidopsis genotypes to the ISS: one wild type and one mutated. The proposed question: How does microgravity affect vacuoles, the plant cell’s largest internal structure that contributes to plant growth.


The experiment itself was testing whether microgravity affects the fusion of some compartments inside the cell. So if you look at a plant cell, there’s a large compartment called the vacuole and these vacuoles need to fuse all the time as the cells grow. And so we were asking whether microgravity had any effect, either accelerating or slowing down the rate of fusion of these organelles.

What we found was that it’s complicated. So we looked at least two different cell types within the root, and we could detect some differences in one cell type, but not the other. And this was both in the wild type, but also in the mutants, in the plants that have abnormal vacuoles in the first place. But surprisingly, we found that overall as a whole there were no major, major defects on vacuole fusion as a whole. So most of the cells had a normal number of vacuoles indicating that, that even in the, you know, stressful conditions of the ISS, which include microgravity, radiation and, and differences in, in how the gases move and stuff, even in those conditions, these particular process was somewhat normal. And so that was a little bit surprising, maybe not in hindsight, but there were not major, major differences. We did detect some small differences, again, in some cell types, in some types of cells, and in the mutant, but overall, you know, these vacuoles were growing fusing. This sort of explains why plants actually grow almost normally in terms of how fast they grow in space, because the vacuoles actually required for that process.


This one experiment will help Rojas-Pierce’s research on plants back in her lab as well as indicate that it is possible to grow plants in space.


We want to be able to grow plants in space effectively, and you can grow plants. They’re not a hundred percent normal. They have some stress responses and things. And so we wanted to know how the vacuole was contributing to that in terms of applications on Earth. Our research program, it’s very fundamental, but at the end it really informs how plants grow in stressful environments, how they adapt to different conditions because the vacuole is very dynamic. So the other part of the labs is changes in vacuole morphology, as the plants are exposed to light and dark. And so all of this knowledge can help us inform other aspects of plant biology and plant physiology, et cetera.


The research also will help inform agriculture back on Earth.


Understanding the fundamental aspects of how plants grow is gonna eventually help us, maybe adjust plants and make changes in plant growth that will make them more resilient in general. Um, because again, the risk of not having a good crop, when, you know, the only crop you have is the one that you’re growing, in an aircraft then, then it’s, it’s pretty serious.


One of the other take-aways from the experiment is the experiment protocol that Rojas-Pierce developed for the astronauts. It was no easy feat.


You have to do the experiment three times at Kennedy to make sure that every single step that you do to set up the experiment is correct is gonna work. So there were issues with contamination of the seeds. There were issues of application of chemical solutions into the seedlings. There were issues about how much the seeds would grow in a certain amount of time. And then what happens with the plants after the experiment is completed, we have to bring them back. So they have to be kind of fixed so that we can analyze the plants under the microscope. And so everything had to be tested and retested. And we had to, we had to demonstrate to NASA that we were ready.

It’s a very expensive experiment. So they wanna make sure that when it goes, it’s gonna be successful. So we had to go three times and run, basically run a mock up of the experiment in their growth chambers, but using all the hardware in all the solutions, everything like it’s gonna be when it goes to the ISS. And, and so the first time we did it, I mean, we had, and that’s when you figured out all the problems that you have in the experiment. Sothe first round was a disaster and the second time it got better and we used it to improve all the protocols and the solutions that we were using. And, you know, how many days we’d grow our plants and, and all of that. And so by the end of the third time, we told them we’re ready. And then they gave us a green light.

HOST: Once the protocol was perfected, they handed it off to the astronauts to carry out on the ISS.


And our experiment is very hands off. So we feel this hardware, which are these little box metal boxes with all this stuff. And all they had to do was, you know, take it out of the cooler, put it at room temperature, and then they had to, you know, push basically like a syringe on it and a couple of times, and then they were basically done. And so it’s an experiment that is very efficient in terms of astronaut time, which is very, very expensive and hard to get.


The protocol is a science that can be used on future experiments for plants in space. Rojas-Pierce is thrilled with the initial results as well as the overall experience.


There are lots of experiments that have been sent that use plants that ask all kinds of questions, but the experience of being there and actually seeing these aircraft, you race up and knowing that your plans are there. . .That is super, super exciting for sure.


To learn more about Rojas-Pierce’s research, check out the CALS Magazine article “Plants in Space” now available at Discover all the other ways CALS students and faculty are tackling the next frontier.

Thank you for joining us on Farms, Food and You. This podcast is a product of NC State Extension and the College of Agriculture and Life Sciences at North Carolina State University. If you would like to support the show, please share this episode on social media and leave a review on your podcasting app of choice. Let’s talk soon!

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