Shaping the rhizosphere: How barley domestication altered root traits and microbiome interactions

Abstract

Climate change and soil degradation are rapidly transforming agricultural systems, underscoring the need for a deeper understanding of how crops interact with their surrounding microbiomes. Barley, as one of the earliest domesticated cereal crops, serves as a valuable model for investigating the effects of domestication on root traits, exudation patterns, and microbial associations. Domestication has influenced not only crop yield but also root morphology and function. This review synthesizes current knowledge on the structural and biochemical modifications in barley roots induced by domestication and examines their implications for microbial recruitment and function. Particular attention is given to how variations in root morphology, the composition of root exudates, and the assembly of microbial communities shape plant–microbe interactions and influence overall crop performance. The impact of modern breeding practices is also explored, with a focus on whether elite cultivars may have lost beneficial microbial partnerships that could be harnessed for future crop improvement. By evaluating contrasting findings and identifying research gaps, this review highlights the need for integrative research approaches, especially those involving multi‐omics and genotype–environment–microbiome frameworks, to better understand the causal links between domestication traits and microbiome dynamics. Ultimately, it advocates for microbiome‐informed breeding strategies that reintroduce beneficial microbial associations from wild barley genotypes. Such approaches hold strong potential to enhance nutrient‐use efficiency, stress resilience, and sustainability in modern agriculture.