By Casey Lowe, a Virginia Tech senior majoring in Humanities, Science, and the Environment in the College of Liberal Arts and Human Sciences
Between 1845 and 1849, the Irish Potato Famine destroyed crops and ultimately killed more than 2 million people in Ireland. The culprit? A highly destructive oomycete pathogen called Phytophthora infestans. Oomycete pathogens are a class of eukaryotic microbes that are similar to fungi and are well known for their destructive history.
Relatives of the oomycete pathogen that destroyed Ireland’s main food source in the 19th century are being studied at Virginia Tech today. Unlocking their genetic secrets could provide powerful benefits to agriculture worldwide. Plant disease causes a 15-20% yearly reduction in global crop productivity, and in today’s growing world food stability is volatile. By 2050 the world’s population is projected to have risen by 30% indicating the rising importance of food production efficiency and stability. That’s where plant pathologists come in.
Kasia Dinkeloo of Delaware, a fourth-year Ph.D. student in the department of plant pathology, physiology, and weed science in the College of Agriculture and Life Sciences, is working with John McDowell and Guillaume Pilot, both professors in the department, as well as four fellow graduate students, to analyze the manner in which oomycete plant pathogens invade plant hosts and extract nutrients.
Kasia found her interest in plants as a high school student. Her original plan was to attend art school, but after reading many books on plants for an art project she found a new passion to become a scientist, a route she also believed would be much more beneficial for her life. While completing her undergrad at the University of Delaware, Kasia took a class on plant pathology and immediately knew it was the direction she wanted to take.
She and her team, directed by McDowell and Pilot, operate in two different labs in Latham Hall investigating the mechanisms by which oomycetes alter the host plants metabolism to fit their nutrient requirements. Some oomycetes are challenging to study because they are biotrophic, meaning the organism must remain in the living host to complete its life cycle, and therefore cannot be cultured or grown away from the plant in order to be studied.
Much like humans, plants have complex and efficient immune systems consisting of a network of thousands of proteins working together. However, plant pathogens can still successfully invade and extract resources from the host plant by overcoming the plants immune responses. The mechanism by which oomycetes suppress plant immune responses is well studied and increasingly understood, but little research or knowledge exists that explains how pathogens trick the plant into giving away its nutrients. For Kasia, this unknown is the most exciting part of her graduate research, but also the most challenging.
For the past three years, Kasia has been developing a method which will eventually allow the team to isolate the specific cells that contain the oomycetes feeding structures from the bulk plant tissue. Once Kasia’s molecular technology is complete, the team will have access to RNA data that should contain genetic evidence of how oomycetes are capable of their takeovers. This information will bring the team much closer to their end goal: to create genetically modified versions of these plants that will resist nutrient extraction by the pathogen.
The test subject is a plant known as Arabidopsis thaliana, a commonly used model organism for pathology studies. The oomycete Hyaloperonospora arabidopsidis is a natural pathogen to Arabidopsis thaliana, making it a perfect candidate for the studies. By understanding how oomycetes successfully hijack nutrients from Arabidopsis, Kasia will be able to isolate the enabling traits and then create modified plants that suppress or are unaffected by the pathogen interference. This will help create plants that won’t give up their nutrient sources, cutting the supply line to the pathogen.
Kasia is well aware of the economic value of her research beyond its scientific implementations. “The value of our science is a dollar value,” said Kasia. “If we can create healthier plants with a higher yield, it will decrease food prices, something the consumer will see in the grocery store and directly benefit from.”
Using pesticides for the chemical control of pathogens has been successful in some ways, but they have caused irreversible environmental damage as well as generated new pathogens resistant to pesticides. By creating modified plants with a genetic defense against oomycetes, the need for pesticides could be eliminated altogether.
According to Kasia, genetically modified plants will be essential for feeding our growing population. She believes creating more food on less land will only be accomplished by working on the plants themselves, not just the environments in which they are grown and produced.
“I’m going to feed the world, that’s the dream! Food is security,” she said.
Q&A: Meet Kasia
Hometown: Wilmington, Delaware
Major/Year: Fourth-year Ph.D. student
Fralin Advisors: John McDowell and Guillaume Pilot
Other Degrees: Bachelor of Science from the University of Delaware
Why do you want to be a scientist?
I really enjoy plant science because it’s a really beautiful way to see the world. I like knowing that the work I do is not only very fulfilling to me as a person, but can be used to help feed our population.
What created your interest in plant pathology?
I knew that plant science/plant pathology was for me after a freshman year course at U.D. called “People and plants: feast or famine.” I loved learning about how plant pathogens and plant growth shaped so much of history, and how understanding plant disease is a key part of food security for the future. After that class, I guess I was hooked.
Career goals after graduate school?
As far as ultimate career goals after the Ph.D., it’s hard to give a clear answer since I am so undecided. But whether I am in academia or industry, I would really love to keep exploring different aspects of plant-pathogen interactions and stay as close to a research lab setting as possible.
Favorite hobby outside of school?
I have a dog; he’s the best ever. I really like having a dog because it reminds me to go home and not spend all day in the lab. I love hiking and outdoor activities as well as powerlifting.
Favorite thing about Blacksburg?
People here are so nice! I thought I was nice when I moved here, but I was just nice for Delaware. There is such a good sense of community here.