Andrew Palmer, associate professor in ocean engineering and marine sciences at Florida Tech, runs a research lab in the Olin Life Science building focusing on how plants communicate with each other and with microorganisms. Using this research, Palmer and his team are exploring how plants could be grown on Mars.
“My lab works at the interface between biology and chemistry,” Palmer said. “We work on this phenomenon called quorum sensing.”
Quorum sensing is, “regulation of gene expression in response to fluctuations in cell-population density,” according to a report published in the National Library of Medicine. Palmer explains quorum sensing as how microorganisms change their behavior based off of how many other microorganisms are around.
Palmer further explained that when there are only a few microorganisms near each other, they might act one way, but when there are up to a billion of the organisms in that place, they can change their behavior.
“This comes out a lot in disease… if there are only a few [pathogens] they won’t do anything but when there are a bunch… they can do something bad like attack your body,” Palmer said.
He explained that bacteria exchange chemical signals, alerting the other bacteria to begin certain processes.
In addition to bacteria, plants also receive these signals.
“Plants are able to eavesdrop on the conversation, figure out what's going on and sometimes even change the conversation a little bit,” Palmer said.
The lab is also studying how plants or the bacteria are going to be able to be used to grow food on Mars.
“We need to take what we know about how plants communicate with one another, and how plants communicate with microorganisms and introduce that into the Mars system,” Palmer said.
Palmer explained that while long term human missions to Mars are at least a decade away, the lab can still plan ahead.
“When the engineers are planning the trip and start putting all the pieces together, we can say ‘this is what you need to take with you, in order for plants to grow,’ rather than trying to figure it out when we get there,” Palmer said.
Because of the atmosphere, freezing temperatures and radiation on Mars, plants need a different way to sustain themselves on the red planet.
Palmer said that greenhouse structures can provide Earth-like conditions for plants.
Regolith: Mars’ substrate for plants
Regolith is the rock and dust found on Mars that can be used as a substrate for plants to grow.
“Organizations have made simulants for the surface of Mars based on rovers and probes that have gone to Mars before,” Palmer said. “We collect those and test to see which ones are the best at supporting plant growth.”
David Handy is a graduate student studying biological sciences. He has been working on the Martian regolith project since 2016.
His main focus in the lab was on perchlorate remediation for regolith.
Perchlorate is a natural impurity also found on Earth, where it is used to create nitrate fertilizer. His research involves isolating particles in this Martian soil in order to determine which samples are most suitable for plant growth.
Handy said the lab is a team-oriented space that also allows for independent growth with opportunities like subprojects.
“I didn't expect to be in such a group environment, [or] expect to be put in charge of any projects when I went in,” Handy said.
Handy explained that his favorite part of working with the lab is going to conferences to present research.
“I'm very weird in that I actually enjoy the public speaking aspect of science where I get to get up in front of a bunch of strangers and talk about the cool work I did,” Handy said.
Kirstin Cutshaw, a graduate student in biological sciences, is working on quorum sensing for a specific algae, Chlamydomonas.
She said her favorite part of working in the lab is the experiment process.
“We're trying to figure out what this molecule is, and we're coming at it from a whole bunch of different angles and devising that plan is really interesting to me,” Cutshaw said.
Cutshaw explained that scientists have studied quorum sensing in bacteria for over 50 years, and that most species have some form of it.
According to Cutshaw, it’s a logical explanation for most unicellular organisms to have evolved the same phenomenon in response to environmental challenges.
“To find it in yet another unicellular eukaryote is exciting. It's fascinating that we're finding this strategy to be more common than originally thought,” Cutshaw said.
Learn more about the Palmer Lab here.