Wheat microbiome interactions under climate change: Mechanisms of abiotic stress tolerance and sustainable crop...

Climate change-induced stresses, including drought, heat, and salinity, are increasingly constraining wheat productivity globally and pose a significant threat to global food security. Although beneficial rhizosphere microorganisms are known to enhance wheat stress tolerance, the mechanisms underlying wheat-microbiome interactions under climate-stress conditions remain poorly understood. This review highlights that wheat actively recruits and reshapes stress-resilient microbial communities, particularly members of Bacillus and Pseudomonas, which promote stress adaptation by regulating reactive oxygen species (ROS), phytohormone homeostasis, nutrient acquisition, and stress-responsive signalling pathways. Furthermore, wheat domestication has altered plant-microbe interactions, resulting in substantial differences in microbiome composition and functional potential between modern cultivars and their wild relatives. The wheat rhizosphere is a dynamic ecological interface where roots interact with diverse microbial communities that influence plant growth, nutrient cycling, and resilience to environmental stresses. This review synthesizes current knowledge on the effects of climate change on wheat physiology, growth, and rhizosphere microbiome composition, while examining how soil physicochemical properties shape microbial assembly and function. Particular emphasis is placed on the mechanisms by which beneficial microorganisms alleviate abiotic stress, including modification of root system architecture, antioxidant regulation, indole-3-acetic acid (IAA) production, osmolyte accumulation, nutrient mobilization, and mitigation of stress-induced ethylene through ACC deaminase activity. We also discuss plant-microbe communication networks mediated by root exudates, microbial signalling molecules, and hormonal crosstalk that govern microbial recruitment, colonization, and establishment within the rhizosphere. Recent advances in genomics, transcriptomics, proteomics, metabolomics, and integrated multi-omics approaches have revealed that wheat dynamically restructures its microbiome in response to environmental stress, with host genotype serving as a key determinant of microbial community composition and function. By integrating evidence on soil properties, microbial functional traits, rhizosphere community dynamics, and wheat stress adaptation, this review provides a comprehensive framework for understanding microbiome-mediated stress resilience. Despite considerable progress, significant knowledge gaps remain regarding microbial community stability, functional redundancy, and the long-term field performance of microbial consortia across locations, seasons, and combined stress scenarios. Addressing these challenges through the integration of multi-omics technologies, microbiome-assisted breeding, synthetic microbial consortia, and climate-smart management strategies will be essential for developing resilient and sustainable wheat production systems under changing climatic conditions.