Synthetic microbial communities for engineering climate-smart biofertilizers.

Global agricultural productivity is increasingly destabilized by climate change-driven droughts, floods, extreme heat, and severe storms. Although the climate-smart agriculture (CSA) framework addresses these challenges, implementation has focused mainly on plant genetics and agronomic inputs, leaving the adaptive potential of the crop microbiome underexplored. Here, we examine the agricultural use of synthetic microbial communities (SynComs) through the "crop holobiont" concept, in which plants and their associated microbiota function as an integrated, responsive system rather than through plant genomes alone. Pioneer plants in extreme environments may serve as reservoirs of stress-adapted microbes and provide a strategic toolkit for advancing CSA. SynComs assembled from these microbes can act not only as nutrient suppliers but also as dynamic physiological modulators that enhance crop phenotypic plasticity under climatic stress. We propose a roadmap for crop microbiology that integrates synthetic ecological engineering, with broad implications for CSA.