Transplant Science

BTI researchers look to replicate plant disease suppression by understanding microbial communities in the soil.

by Sarah Perdue

Crop loss due to disease is a major factor in the use of pesticides, but current BTI research is hoping to decrease pesticide use while also increasing crop yields. “We know that some soils are more disease suppressive than others, and the same crops grown in disease suppressive soil are healthier than those grown in normal soil,” said Zewei Song, a postdoctoral fellow in plant pathology. His work, which could lead to less pesticide runoff from farmland into lakes and streams, is funded in part by a MnDRIVE: Environment postdoctoral fellowship. “What is more amazing is you can inoculate this disease suppressive soil into sterile soil and this soil becomes disease suppressive,” Song added, likening this process to microbiota/fecal transplantation in humans, also being studied at the University. “We want to find the biological mechanisms that make soils disease suppressive and reproduce this outcome in agricultural fields.”

Researchers have long known that competition amongst microbes plays an important role in antibiotic production and plant health, but studies have often focused on one species at a time, or interactions between only a few species. Song and his colleagues want to study the systems of soil microbes as a whole to better understand how their interactions lead to plant disease suppression. If they can understand how soil microbes suppress plant disease, then they can more quickly mitigate the effects of crop pathogens. “We’re adding carbon sources into the soil to increase competition, then we’re measuring plant disease, such as scab on potatoes, and sequencing the microbial communities to identify their structure,” Song said. “We’re trying to see if we can increase disease suppression with these carbon additions and understand the responses in the microbial community structure over time.” Linda Kinkel, Professor of Plant Pathology and lead investigator of the study, said the field study is in its second season so the microbial community structure changes have not yet been analyzed. “We saw good responses in terms of reductions in disease and enhancements in plant productivity during the first season of the study,” she added.

Kinkel said that this project builds on a USDA-funded project, but without MnDRIVE they would only have had funding to investigate the effects of carbon amendments on the plants. “The USDA study allows us to measure the plant response to the treatments, but MnDRIVE provides the funds to collect data on shifts in soil community composition and diversity following treatment,” Kinkel said. “There’s synergy there. The whole really is greater than the sum of the parts.” Kinkel added that Scott Bates, former Assistant Professor in Plant Pathology and partner on the project, has contributed significant expertise to the analyses of the fungal communities in the treated plots. Song noted that increasing crop yields could do more than simply add to the food supply. It could also lead to more efficient alternative energy production. “In a shift to more biofuel production, the Department of Energy requires you to grow biofuel crops that don’t compete with traditional crops,” he said. “If you can reduce crop loss before harvest, then you can produce both food and biofuel without compromising either.”