UC chemistry researcher studying viruses in plants | Andrew Higley/University of Cincinnati
Plant viruses are a substantial and recurring problem in agriculture and horticulture. Just within the U.S., annual costs lost due to crop diseases are estimated at over $20 billion. Therefore, something must be done to stem the flow of this destructive tide.
Thankfully, a handful of researchers at the University of Cincinnati are currently working on finding an easier and faster way to diagnose plant viruses. Their goal is to find a method that is quick and accurate enough to identify such issues before they infect entire crops, allowing for targeted disposal and removal instead of complete batch failure.
The students involved in the effort at UC Assistant Professor Pietro Strobbia’s lab are examining efficient methods that can detect viruses in plants before the appearance of common symptoms, such as yellowing and leaf spotting.
Part of this project involves collaboration with researchers at the University of Kentucky to develop hydrogel sensors, which can detect pathogens when in contact with leaves. According to UC News, the researchers “abraid the leaf and apply a hydrogel sensor, which uses spectroscopy to “fingerprint” the chemicals found in the sample,” leaving any present virus with nowhere to hide. However, Strobbia and his students are now refining the process to use microneedles instead of hydrogel for an easier testing method.
The project is currently focused on studying the tobacco mosaic virus (TMV) due to its ability to infect hundreds of different plant species. Named for its mosaic pattern of light and dark colors on infected leaves, the virus is spread through direct contact, as well as secondhand through insects and workers.
Research documented by Penn State Extension claims that the virus “can also survive outside the plant in sap that has dried on tools and other surfaces. If a TMV plant is handled and then you open a door with that hand, you have now put TMV on the door handle. The next person to open the door can pick up the TMV and spread it to any plant that they touch.”
There is no identified cure for TMV, so the only solution is to destroy infected plants.
Current identification methods of TMV require complicated molecular tests and visual inspections of plants, which aren’t always accurate. This contributes to incorrect identification and undiagnosed plants, leading to excess waste in the industry.
“The diagnosis of plant infection relies on visual cues,” said Lyndsay Kissell, a U.S. Food and Drug Administration (FDA) chemist who previously worked as a Postdoctoral Research Fellow at UC in Strobbia’s lab. “That means the plants are already sick enough to show symptoms. If we can diagnose these infections sooner, then farmers would be able to isolate infected plants and remove them before infection spreads throughout a field.”
UC doctoral student Manisha Sheokland says the sensors they’re developing in Strobbia’s lab are inexpensive, in addition to being more accurate and easier to use than past methods. “This approach is aimed to be field-deployable, cost-effective, reliable, and allow real-time detection of plant viruses,” she says.
The challenge of this research was being able to identify low concentrations of the virus, which is critical for early detection before it spreads.
“Because we wanted to detect these infections early, we had to be able to sense even when the viral load was low. By using a hydrogel matrix, we were able to overcome both of those challenges,” says Kissell.
Kissell says these early detection methods could make a huge difference for growers. “I grew up around farming communities and know what a poor yield year can mean. With early diagnosis, perhaps we can lessen that impact.”
