Harnessing plant-microbe interactions for climate-adaptive agriculture: Mechanisms, applications, and future perspectives

Climate change presents an unprecedented threat to global food security by intensifying abiotic and biotic stresses on agricultural systems. Climate-adaptive (or climate-smart) agriculture has emerged as a crucial framework for developing resilient food production systems. Within this framework, leveraging beneficial plant-microbe interactions represents a sustainable and potent strategy to enhance crop productivity and stress tolerance. This review synthesises the current understanding of the mechanisms through which plant growth-promoting microorganisms (PGPMs), including rhizobacteria, endophytic bacteria, and mycorrhizal fungi, bolster plant resilience. Key mechanisms discussed include enhanced nutrient cycling (nitrogen fixation, phosphorus solubilization), phytohormonal regulation (e.g., auxins, gibberellins, ACC deaminase activity), and the induction of systemic resistance against pathogens. The paper examines how these interactions mitigate the impacts of major abiotic stresses such as drought, salinity, and extreme temperatures by improving water acquisition, managing osmotic and ionic stress, and neutralising oxidative damage. A comparative analysis of recent field and lab studies highlights the efficacy of specific microbial inoculants, such as Bacillus, Pseudomonas, and Glomus species, in improving crop performance under stress. Furthermore, this review explores future research frontiers, focusing on the transition from single-strain inoculants to the design of complex, metabolome-derived synthetic microbial consortia (SynComs). We discuss the pivotal role of multi-omics technologies in deciphering these intricate interactions and address the practical challenges of scaling up microbial solutions from the laboratory to the field. The paper concludes that microbial-based innovations are fundamental to building the next generation of sustainable and climate-resilient agricultural systems.