Rhizosphere microbiome may help crops withstand heat stress

North Carolina State University researchers linked microbial D-amino acid metabolism to plant heat tolerance in maize and sorghum in 2026.

Published in New Phytologist, “Investigating GERMs: how genotype, environment, and rhizosphere microbiome interactions underlie heat response in maize and sorghum” used a Genotype × Environment × Rhizosphere Microbiome model. The team compared two inbred maize lines with contrasting heat sensitivity and one sorghum inbred with moderate heat tolerance across two soil treatments, then grew the plants under optimal and heat-stressed regimes listed in the USDA National Agricultural Library dataset as 20/28 and 28/38.

Using a systems-level metatranscriptomics approach, the researchers combined plant and microbial transcriptomic profiles with microbiome compositional data and plant phenotypes. Host genotype and temperature were both associated with changes in microbial function, and conserved plant orthologs across maize and sorghum were linked to microbial pathways.

The most specific pathway signal was microbial D-amino acid metabolism, which the paper linked with plant heat tolerance. The work first appeared as a bioRxiv preprint in December 2025 before the peer-reviewed version was published in 2026.

Maize is a core U.S. agricultural crop, and sorghum is a potential bioenergy feedstock.

Nate Korth said further research will focus on whether scientists can influence the rhizosphere microbiome to impart specific benefits to plants. The USDA issued an interim rule in January 2025 on technical guidelines for climate-smart agriculture crops used as biofuel feedstocks, including corn, soybeans and sorghum, and then a final rule on regenerative agricultural biofuel feedstocks on June 25, 2026. The USDA National Agricultural Library dataset for the study lists 3 genotypes, 2 soil treatments and dual transcriptomics files with microbe and plant RNA reads.