Title : Nurturing resilience: Harnessing synthetic microbial communities from root microbiomes to mitigate drought effects on pasture production
Abstract:
Climate change-induced drought is an escalating challenge for global agriculture, with New Zealand already experiencing significant economic losses from reduced pasture productivity. Projections indicate that drought events will increase in both frequency and severity, underscoring the urgent need for sustainable mitigation strategies. Microbial communities associated with plants are known to influence drought resilience, presenting a promising avenue for intervention. This study aims to develop a stable microbial synthetic community (SynCom) from drought-resilient microbes inhabiting the rhizosphere and endosphere of pasture plants. The research is structured into two stages. In the first stage, microbes will be isolated from plants naturally growing in dryland regions and screened for plant growth–promoting traits, including indole acetic acid production, phosphate solubilization, and siderophore activity, alongside tolerance to osmotic stress (sorbitol and polyethylene glycol assays). In the second stage, selected isolates will be combined into SynComs and evaluated under controlled glasshouse conditions for their capacity to enhance drought tolerance in pasture species. Plant responses will be assessed through growth (shoot and root biomass) and physiological indicators such as leaf chlorophyll content, relative water content, antioxidant enzyme activity, and stomatal conductance. A small-scale drought trial with plantain will first be used to identify stable SynCom members via amplicon sequencing, from which a drought-resilient SynCom will be selected for larger experiments involving white clover, perennial ryegrass, and plantain. The outcomes of this research will provide a framework for designing microbial inoculants tailored to New Zealand pasture systems. More broadly, the development of effective SynComs has the potential to contribute to sustainable agricultural practices worldwide by enhancing plant resilience to climate change–induced drought stress.
