Microbial partners may help plants respond to higher temperatures
New research suggests the microbiome near the surface of a plant’s roots, known as the rhizosphere microbiome, may play a role in helping crops respond to heat stress.
When studying adaptation in living things, scientists sometimes analyze the interplay between genetics and environment to influence measurable traits, a phenomenon known as Genotype by Environment interactions (GxE). Now, researchers from North Carolina State University have added the rhizosphere microbiome to the GxE framework, resulting in a new model named Genotype by Environment by Rhizosphere Microbiome interactions (GERM).
The researchers analyzed the function of microbes collected from the rhizosphere of maize and sorghum plants grown in both optimal and heat-stressed conditions. They found that the host plants’ genotype and the surrounding temperature were both associated with changes in microbial function.
Nate Korth, lead author of the paper and a post-doctoral fellow in NC State’s Department of Crop and Soil Sciences, said this could be a sign that those microbes help “turn on” certain genetic responses to environmental factors.
“We think this heat basically signals to the plant that it needs to activate a specific set of genes that would normally be dormant,” he said. “We can tell that there is a relationship here, that there is communication between the host plant and the microbes that live on it.”
What researchers need to understand now is the “direction” of that communication. It’s a “chicken-and-egg” situation where researchers don’t yet know which comes first – the genetic responses of the plant causing changes in the microbiome, or signals from the microbes triggering genetic responses in the plant.
Further research may focus on applications for this new knowledge, including if scientists can influence the rhizosphere microbiome to impart specific benefits to plants, Korth said.
The paper, “Investigating GERMs: how genotype, environment, and rhizosphere microbiome interactions underlie heat response in maize and sorghum,” is published open-access in New Phytologist. Isabella Borrero, Katelyn Rumley, Alex L. Woodley, Mallory J. Choudoir and Joseph L. Gage of NC State University are co-authors of the paper.
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Note to editors: An abstract follows.
“Investigating GERMs: how genotype, environment, and rhizosphere microbiome interactions underlie heat response in maize and sorghum”
DOI: 10.1111/nph.71297
Authors: Nate Korth, Isabella Borrero, Katelyn Rumley, Alex L. Woodley, Mallory J. Choudoir, Joseph L. Gage, NC State University
Published: May 26, 2026 in New Phytologist
Abstract: Three genotypes – a heat-resistant maize (Zea mays), a heat-susceptible maize, and a sorghum (Sorghum bicolor) variety – were grown to the V4 stage in growth chambers under optimal conditions or subjected to heat stress. Plants were grown in soil containing a complex microbial community, or in the same soil with a depleted microbiome. Total RNA from roots and root-associated microbes was sequenced, along with the 16S rRNA amplicon from both DNA and RNA. Plants were assigned a qualitative heat stress score based on size and leaf senescence as well as quantitative metrics, including biomass and root architecture.