Rhizosphere engineering for crop resilience to abiotic stress

Overview

This research focuses on rhizosphere engineering to improve crop resilience to abiotic stress, specifically drought and salinity in wheat. By applying forced evolution techniques to beneficial root-colonizing bacteria, the project aims to select microbial strains with enhanced stress tolerance and probiotic activity. These stress-evolved bacteria produce EPS-rich biofilms and release beneficial metabolites and osmolytes that help host plants cope with adverse environmental conditions. The approach offers a biological, sustainable alternative to chemical inputs for improving crop performance in challenging agricultural environments.

Technical specifications

Key features:

• Isolation of bacteria from wheat roots grown in calcareous agricultural soils with diverse management practices, pH, salinity, and carbon profiles
• Forced evolution approach using sequential stress exposure on agar plates with increasing NaCl and PEG 8000 concentrations to select stress-resilient microbial isolates
• Defined growth media simulating measured wheat root exudate profiles to mimic rhizosphere conditions during selection
• Single and mixed culture inoculation strategies for surface-sterilized wheat seeds
• Assessment of plant vigor through CO2 assimilation rates, transpiration, and photosynthetic efficiency measurements
• Evaluation of bacterial modes of action, including EPS-rich biofilm production and osmolyte release

Technology readiness level

The research is at an early-to-mid stage of development. Initial validation has demonstrated that bacterial mixtures isolated from wheat roots increased CO2 assimilation rates compared to non-inoculated plants, and five specific strains improved CO2 assimilation with two significantly enhancing wheat growth under drought conditions. Future validation will subject the most promising isolates to forced evolution under salinity and water stress, followed by testing in agricultural soils with wheat grown up to 28 days under drought and salinity stress conditions. Single and mixed inocula will be examined to identify optimal formulations for improving plant vigor.