Scott Peck

Family genes

MU freshman follows in aunt’s footsteps while exploring career options

Robert Schmidt poses with one of the cats that lives at Horton Animal Hospital, where he works part-time. Schmidt, a freshman studying biochemistry at the University of Missouri, is a member of the Discovery Fellows Program.

Robert Schmidt poses with one of the cats that lives at Horton Animal Hospital, where he works part-time. Schmidt, a freshman studying biochemistry at the University of Missouri, is a member of the Discovery Fellows Program where he is learning about plant genetics by working with biologist Scott Peck in the Bond Life Sciences Center. Photo by Justin L. Stewart | MU Bond Life Sciences Center

By Justin L. Stewart | MU Bond Life Sciences Center

Sometimes it’s socks. Another time, it was a book cover.

Robert Schmidt has retrieved quite a few things from misguided pets’ digestive systems as an assistant at Horton Animal Hospital, where he’s worked with his aunt for the past three years.

While most of the time he helps with simpler things — such as feeding kenneled animals or spaying and neutering pets — he also has amputated a dog’s toe after it had a lawnmower mishap.

Schmidt says he’s kind of following in his aunt’s footsteps. She majored in biochemistry at the University of Missouri and studied at its veterinary school, too. That’s what Robert wants to do with his life.

Schmidt demonstrates how to apply ear medication to a nervous small dog at Horton Animal Hospital on Forum.

Schmidt demonstrates to a pet owner how to apply ear medication to a nervous small dog at Horton Animal Hospital on Forum. Schmidt works at the animal hospital part-time with his aunt. Photo by Justin L. Stewart | MU Bond Life Sciences Center

Schmidt likes working with animals, but pets aren’t the only animals he’s interested in. An internship at the MU Animal Sciences Research Center two summers ago had Schmidt elbow deep in fistulated cows’ stomachs as he assisted in research that tested the affects of adding different metals in cows feed to help them better absorb protein.

“My family’s always had a dog, my sister has a cat and I work at a small animal clinic. For a while, I was just like, ‘I’m not going to work with cows. I didn’t grow up on a farm.’ But now, after the internship, I’m interested in getting some more experience.”

As a freshman in the Discovery Fellows Program, Schmidt now finds himself knuckle deep in dirt as he digs into plant genetics.

The Discovery Fellows Program pairs first-semester freshmen and sophomores with scientists in their chosen field, allowing them to get hands-on experience in research on campus while earning a $1,700 stipend.

That led Schmidt, an MU Honors College student, to the lab of biologist Scott Peck in the Bond Life Sciences Center.

Schmidt plants Arabidopsis seeds in a petri dish.

Schmidt plants Arabidopsis seeds in a petri dish inside the Bond Life Sciences Center, where his fellowship work is. Photo by Justin L. Stewart | MU Bond Life Sciences Center

Peck studies how plants recognize and respond to infections, specifically focusing on three proteins that begin to chemically modify shortly after a plant is infected.

No one knows what these proteins actually do, Peck said, making the research that much more interesting.

Schmidt has been growing Arabidopsis seeds of three different types, each missing one of the three proteins. Once those seeds have fully grown, Schmidt said they will cross-pollinate the three variations to hopefully create a plant without any of those three proteins.

He hopes to have triple mutants by early next semester, so they can experiment with them to better understand the roles of the absent proteins.

While Schmidt came into Peck’s lab with more of an interest in animals, he sees how the skills translate.

“If I worked with animals, I’d want to do genetics and I’m doing genetics with plants right now. A lot of the lab techniques are transferable.”

Schmidt moves an Arabidopsis seedling from a petri dish to fresh soil with the rest of the grown seedlings. Arabidopsis can grow from seed to seedling with two weeks. It's a favorite among scientist, according to the National Science Foundation.

Schmidt moves an Arabidopsis seedling from a petri dish to fresh soil with the rest of the grown seedlings. Arabidopsis can grow from seed to seedling with two weeks. It’s a favorite among scientist, according to the National Science Foundation. Photo by Justin L. Stewart | MU Bond Life Sciences Center

Like most freshman, the former Rockbridge Valedictorian is still figuring out his life plans. He’s considering a double major in math, a favorite subject of his, and now wonders whether he might attend graduate school instead of vet school.

“I really like learning, being in a classroom and being a student. I really enjoy that. I think research is almost like a career where you’re almost always a student. You’re just always learning.”

As for now, he’s just waiting for his first batch of Arabidopsis seeds to mature.

 

Chemical beacons: LSC scientist discovers how plants beckon bacteria to attack

Scott Peck studies Arabidopsis and how bacteria perceive it before initiating an infection. Roger Meissen/ Bond LSC

Scott Peck, Bond LSC scientist and associate professor of biochemistry, studies Arabidopsis and how bacteria perceive it before initiating an infection. Roger Meissen/ Bond LSC

Sometimes plants inadvertently roll out the red carpet for bacteria.

Researchers at the University of Missouri Bond Life Sciences Center recently discovered how a plant’s own chemicals act as a beacon to bacteria, triggering an infection. Proceedings of the National Academy of Sciences published their study April 21.

“When bacteria recognize these plant chemicals it builds a needle-like syringe that injects 20-30 proteins into its host, shutting down the plant’s immune system,” said Scott Peck, Bond LSC plant scientist and lead investigator on the study. “Without a proper defense response, bacteria can grow and continue to infect the plant. It looks like these chemical signals play a very large role in mediating these initial steps of infection.”

The question of how bacteria actually know they are in the presence of a plant has puzzled scientists for years. Being able to identify the difference between a plant cell and, say, a rock or a piece of dirt, means the bacteria saves energy by only turning on its infection machinery when near a plant cell.

“Our results show the bacteria needs to see both a sugar – which plants produce quite a bit of from photosynthesis – and five particular acids at the same time,” Peck said. “It’s sort of a fail-safe mechanism to be sure it’s around a host before it turns on this infection apparatus.”

Peck’s work started with one mutant plant called Arabidopsis mkp1.

Discovered several years ago by Peck’s lab, this little mustard plant acts differently than others by rebuffing the advances of bacteria. Lab tests confirmed that this mutant didn’t get infected by Pseudomonas syringae pv. tomato DC3000, a bacterial pathogen that causes brown spots on tomatoes and hurts the model plant Arabidopsis. Along with MU biochemistry research scientist Jeffrey Anderson and post doc Ying Wan, they showed that this mutant didn’t trigger the bacteria’s Type III Secretion System, the needle-like syringe and associated proteins that lead to infection.

Pacific Northwest National Laboratory (PNNL) worked with Peck’s team to compare levels of metabolites between the mutant Arabidopsis and normal plants. This comparison helped Peck identify a few of these chemicals – created from regular plant processes – that existed in much lower levels in their special little mutant.

Using the PNNL work as a guide, the team found five acids collectively had the biggest effect in turning on a bacteria’s infection: aspartic, citric, pyroglutamic, 4-hydrobenzoic and shikimic acid.

“The key experiment involved us simply adding these acids back into the mutant,” Peck said. “Suddenly we saw the mutant plant wasn’t resistant anymore and the bacteria were once again capable of injecting proteins to turn off the plant’s immune system.”

First contact and recognition means all the difference, whether bacteria or plant. Just a slight jump out of the starting blocks by one or the other could change who will win a battle of health or infection.

While low concentrations of these five acids trigger the bacteria’s attack, high levels blind it to the plant’s presence, leading Peck to believe it could be used to hinder bacterial growth. If this actually thwarts the bacteria’s head start, it could mean stopping disease in crops and could lead to a different approach in the field.

“A lot of the winning and losing occurs within the first 2-6 hours and it seems to be that if the microbe is too slow to turn off the immune system, the plant can actually fight off the infection,” Peck said. “In the future we could possibly make a new generation of anti-microbial compounds that don’t try to kill the bacteria, but rather just make them no longer virulent by blocking these chemical signals so the natural plant immune system can basically take over.”

Peck’s team believes at least some other bacteria will respond to these chemical signals, and he plans to test other bacterial pathogens to make certain. They also want to test bacteria to see if they are more virulent in humans once primed for attack by these plant chemical signals.

“In the long run the question is how far this extends. A lot of people get salmonella or listeria infections through a food source,” Peck said. “The question is do other bacteria that come in through plant food sources have similar perception systems and end up being more infectious in humans because they are already primed for infection.”

A $500,000 grant from the National Science Foundation supported this research.