Microbial exopolysaccharides as bioprotective polymers for plant resilience in climate-stressed agroecosystems

Abstract

Microbial exopolysaccharides (EPS) are multifunctional polymers that play critical
roles in supporting plant resilience under climate-induced environmental stress.
Increasing evidence shows that EPS secreted by rhizobacteria contribute to water
retention, ion chelation, antioxidant activation, immune modulation, biofilm formation
and microbe-plant signaling, collectively enhancing plant tolerance to drought, salinity
and soil toxicity. Despite the recognized ecological functions of EPS, knowledge of
their diversity, mechanisms of action and practical applications in agriculture remains
fragmented. This review synthesized current advances in understanding the structural and
functional attributes of microbial EPS and highlighted representative microbial producers
with plant-protective traits. Emerging applications, including EPS-based biostimulants,
bioformulations, and stress-mitigation tools, were examined critically in the context of
climate-smart and sustainable crop management. In addition, the discussion considered
key challenges, such as variability in EPS production, lack of standardized formulations
and limited field validation. By reframing microbial EPS as biologically active shields in
the rhizosphere, this review underscored their potential to strengthen crop productivity
and agroecosystem stability, as well as further outlining priority directions for research
and policy to translate molecular insights into scalable innovations that address
the challenges of climate-resilient agriculture.