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ARS Home » Pacific West Area » Albany, California » Plant Gene Expression Center » Research » Research Project #436643

Research Project: Molecular Causes and Phenotypic Consequences of Bacterial Enrichment Patterns in the Root Endospheres of Drought-Stressed Crop Systems

Location: Plant Gene Expression Center

Project Number: 2030-12210-002-04-A
Project Type: Cooperative Agreement

Start Date: Apr 15, 2019
End Date: Apr 14, 2020

Objective:
The goal of this project is to investigate the molecular causes of a recently described Actinobacterial enrichment in the root microbiome of crop plants under drought stress, from the microbial and host perspectives, and the phenotypic consequences of this enrichment for the host plant. The team will use a combination of new genomic technologies and microbiome manipulation strategies, in both lab and field-based experimental designs, using Sorghum bicolor , which represents an excellent agronomic model for drought research and an important feedstock and bioenergy crop. The research can be broadly categorized by the central objective of the project: identification consequences of Actinobacterial enrichment for crop fitness. The ARS PI and Cooperator PI will inoculate field grown sorghum with isolates from an in-house collection and assess crop fitness through biomass and growth phenotypes, and profile microbial community composition and richness via metagenomic strategies.

Approach:
To identify the consequences of Actinobacterial enrichment for crop fitness, the Cooperator PI will conduct field trials of sorghum amended with individual drought-enriched isolates and isolate consortium followed by measurements of drought phenotypes, biomass, and grain yield. Initial field trials will focus on establishing most suitable methods of inoculation. To impose drought on this variety, we will plant at the UC-ANR Kearney Agricultural Research & Extension (KARE) Center in California’s Central Valley in Parlier, California. The experimental units will be the status of inoculation, and will include inoculated and uninoculated controls. One row will be used to take measurements of biomass, and grain yield, while the other row for all molecular characterization (16S rRNA amplicon) of the sorghum microbiome. A planting area uniform in soil composition will be used to minimize environmental variation, and several areas at the KARE facility have previously been selected for minimal heterogeneity in microbial constituency. The experimental design will employ two distinct inoculation treatment strategies, namely seed coating and direct liquid media application to seedlings. The success of each inoculation strategy will be measured by degree of isolate colonization of and persistence within the root and rhizosphere microbiomes, as measured by 16S rRNA amplicon sequencing at 2 three points during the sixteen-week growing period (week 2, week 8, and week 14).