Since the earliest days of farming, ensuring adequate food production to consistently feed a population has been the primary goal. This goal has not changed in the thousands of years since plant cultivation began, al though the mechanisms of achieving it have evolved considerably. Irrigation, pesticides, automated machinery—all these advancements have arisen from the need to produce enough food to keep pace with the growing numbers of humans on the planet.
In recent years, this drive has shifted toward the plants themselves. Genetically modified seeds designed to withstand drought and blight have become commonplace. Sarah Lebeis, assistant professor of microbiology, believes the next advances will be made by studying plant microbiomes, specifically the effects of certain bacteria on those microbiomes.
“One thing we’ve found is that the more we look at which microbes associate with plants, we find these bacteria over and over again. They can be pathogens or they can promote growth of the plants,” she said.
Some agricultural companies have seized on the idea that plants can be helped with the introduction of so-called good microbes and have begun marketing products designed to do just that. Lebeis describes these products as plant probiotics and emphasizes that they are not always effective.
“It’s really exciting that people are trying to find these ultimate microbes that can change the way plants grow, but they’re not always going to work. When they don’t work, we want to know why they don’t work,” she said.
She believes Streptomyces, a particularly large genus of bacteria, is playing a role in determining which microbes are allowed into a plant. Lebeis suggests that, in addition to keeping out harmful microbes, the Streptomyces may also be preventing some beneficial microbes from entering the plant’s system.
Lebeis’s ORNL collaborator, Daniel Jacobson, chief scientist for computational systems biology, has provided her team with a large data set to serve as the basis of her JDRD work. By the end of the year she hopes to have compiled a list of microbes that either work with or are repelled by Streptomyces.
“We want to see who they influence, who they let in and who they don’t. The JDRD will help us generate a giant list of hypotheses, which we’re so excited about,” said Lebeis.