An LSU biologist, in cooperation with NASA, has been investigating how plants adapt to toxic soils with high amounts of saline in them, similar to the soil conditions found on Mars.

Maheshi Dassanayake, an associate professor of biological science, said she and her team currently have a number of candidate genes that will be contributors to plants to help them survive in the harsh environmental conditions of Mars. They are currently introducing these genes to crops in order to test whether the crops could be grown in these Martian habitats.

Dassanayake said she became interested in attempting this project because she said, “we cannot envision long-term human habitats without plants on Mars.”

Right now, there are no plants on Earth that can survive the harsh conditions on Mars. 

“As plant biologists, we are interested in contributing to human exploration beyond our planet,” said Dassanayake.

Dassanayake is working with Scott Perl, a research scientist specializing in life in extreme environments at NASA’s Jet Propulsion Laboratory, on the project. 

A challenge Dassanayake has come across in her research has been conducting plant growth tests on Martian soil in order to understand the challenges the soil will present. This data, she said, is currently unavailable and the studies still remain at the planning stage.

The specific issue with Martian soil, Dassanayake said, is its generally high saline content and unspecified amount of water, nitrogen and phosphorus, which can lead to malnutrition. The high levels of saline often impact negative plant growth. There are also heavy metals traced in the soil that are toxic to plants. 

Suniti Karunatillake, associate professor at LSU’s Planetary Science Laboratory, is assisting Dassanayake with her research. He said that Dassanayake is planning to simulate and grow crops under Martian soil conditions to see how they would survive on the Martian landscape. 

He said that Dassanayake is growing these crops with a diverse set of soil analogs that emulate the Martian environment in order for the plants to be ready for the different types of soils encountered on missions to Mars.

According to Karunatillake, three things make Martian soil so hard to grow crops in and sustain a manned mission.

First is the high concentration of iron. While iron is necessary for humans and plants, once the concentration of iron gets too high it can become a source of stress for growth and become toxic for humans to eat. 

The second issue is the atmospheric climate of Mars. The air is very thin, which is difficult for humans to breathe, who need a denser atmosphere like Earth’s to breathe properly.

“It is the density you would experience at the top of Mount Everest,” Karunatillake said.

The final issue is the high sodium content that would enable the ability of plants to grow. Lack of rain or snow on Mars would cause dehydration in the plants, stunting their growth. Karunatillake said that in order to hydrate the soil, they would have to use synthetic waves, which are man-made artificial waves that would be created on the surface of Mars.

The plants that would be the most adaptable to Mars would be the plants that grow in environments with unusually high sodium concentrations. According to Karunatillake, Lake Truz in Turkey is an environment that could simulate Martian soil.  

Lake Truz doesn’t contain any trees, as the soil stunts their growth due to its high sodium and magnesium content. Karunatillake said the plants that live in these zones will be more genetically adapted than regular crops to survive these conditions, similar to those on Mars. These settings also tend to have the high magnesium settings associated with the Martian soil.

The best place on Mars to grow these crops is the Meridian Plains, a large plain stretching across the equator of Mars, Karunatillake said.

“It’s much like a desert on Earth,” he said.
The crops that would grow on Mars should preferably contain all the nutrients in the United States Department of Agriculture Food Pyramid, Karunatillake said. They would contain carbohydrates, iron, vitamins and calcium. The plants would also produce oxygen for the astronauts.

“All of that would come from a mix of the plants’ leaves,” Karunatillake said.