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ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #419793
Research Project: Ecology and Genomics of Soilborne Pathogens, Beneficial Microbes, and the Microbiome of Wheat, Barley, and Biofuel Brassicas

Location: Wheat Health, Genetics, and Quality Research

Title: The rhizosphere microbiome of dryland and irrigated wheat and suppression of root diseases

Author
item Weller, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/10/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: .

Technical Abstract: Root-associated microbiomes are critical to the growth and health of wheat and other crops grown in cereal-based production systems of the Pacific Northwest, USA. The rhizosphere microbiome provides the first line of defense of roots against soilborne pathogens. However, long-term trends in wheat-root microbial community dynamics are poorly understood. This study characterized the growing season and long-term population dynamics of bacterial communities in the rhizosphere and endosphere of wheat grown in monoculture for eight years in dryland and irrigated field plots in Washington State, USA with less than 305 mm annual precipitation. The diversity and richness of bacterial communities declined from the bulk soil to the rhizosphere, and to the endosphere. Bacterial richness and diversity were significantly greater in irrigated wheat. Some genera showed a consistent periodicity in their population trends during the growing season from March to August. Over eight growing seasons, Proteobacteria and Bacteroidetes (Pseudomonas, Variovorax, Chryseobacterium) maintained stable rhizosphere populations in both dryland and irrigated wheat. Populations of some Bacteroidetes and Proteobacteria (Mucilaginibacter, Sphingomonas, Massilia, Burkholderia) were dryland adapted and persisted or increased in the dryland rhizosphere whereas others (Rhizobium, Acidovorax, Terremonas, Hyphomicrobium, Bdellovibrio) increased on irrigated wheat. In contrast, some taxa, including many Actinobacteria, declined in abundance over eight years in both the endosphere and rhizosphere regardless of irrigation. Our results provide insight into how water and monoculture impact the population dynamics of the wheat-root microbiome and the suppression of root diseases.