Root endophytic bacteria collection for crop improvement and drought tolerance

Overview

This offering is a curated collection of approximately 1,000 cultured bacterial isolates representing up to 200 distinct taxonomic units derived from the root endophytic communities of field-grown rice in Northern California. The collection captures the most abundant native root endophytes, which are microorganisms that live within plant root tissues without causing disease. Research has shown that these bacteria are recruited and enriched by the plant itself during different developmental stages and under stress conditions such as drought.

A particularly promising component of the collection is a Streptomyces strain that becomes highly dominant under drought stress, reaching approximately 20% of the root microbiome. This isolate has demonstrated the ability to promote root growth in rice, which enhances drought tolerance. Preliminary data also suggests the strain can colonize the roots of Arabidopsis, indicating potential applicability beyond rice to other crop species. The collection provides a foundation for developing microbial products that can improve crop performance under both normal and water-limited conditions.

Technical specifications

Key features of the collection:

• Approximately 1,000 cultured isolates representing up to 200 distinct operational taxonomic units (OTUs)
• Isolates are non-pathogenic and derived from field-grown California rice
• Whole genome sequences available for approximately 40 isolates
• Includes the most abundant root endophyte taxa, collectively representing over 16% of the root microbiome
• Features a Streptomyces strain enriched under drought that promotes root growth and drought tolerance
• Putative plant growth-promoting genes identified in the Streptomyces genome
• Spore-based delivery format may enable seed coating or other application methods

Research foundation:

• Longitudinal field studies demonstrate plant-driven recruitment and enrichment of specific endophyte taxa
• The drought-enriched Streptomyces OTU was found across three different agricultural fields in Northern California
• Published research has attracted commentary in Nature Plants and PNAS

Technology readiness level

The collection is at an early-to-mid stage of development. The bacterial isolates have been cultured, identified, and partially characterized through genomic sequencing. The Streptomyces strain has demonstrated proof-of-concept for root growth promotion and drought tolerance in laboratory and preliminary plant studies. However, the broader potential of the remaining isolates in the collection remains largely unexplored.

Further characterization and field validation are needed to fully assess the agricultural utility of these endophytes across different crops and growing conditions. Current research efforts include collaborative work with Joyn Bio to advance the development of these microbial isolates toward practical agricultural applications. The technology readiness suggests opportunities for partnership in further validation, product development, and commercialization pathways.