Abstract

Water-scarcity driven by climate change, stagnant agricultural productivity, and rapid population growth trigger food security. Sustainable alternatives such as the use of plant-growth promoting microorganisms (PGPM), including arbuscular mycorrhizal fungi (AMF), yeast (PGPY) and rhizobacteria (PGPR) offer promising sustainable solutions. However, the potential of microbial consortia remains insufficiently explored. This study aimed to evaluate the effects of synthetic microbial communities (SynComs) on the morphophysiological responses of maize, common bean, and squash under drought stress. Six microbial strains (two AMF, two PGPY and two PGPR) were combined into eight SynComs. Seeds were inoculated with AMF at germination, followed by PGPY and PGPR every 15 days after transplanting. Biomass production and leaf water potential were assessed under controlled drought conditions. Water-deficit reduced overall biomass production; yet specific SynComs, significantly enhanced plant performance. Maize and common bean inoculated with the consortium Funneliformis mosseae, Naganishia albida and Bacillus tequilensis showed increases exceeding 40% in fresh and dry shoot and root biomass. Squash inoculated with F. mosseae, Rhodotorula mucilaginosa and B. tequilensis exhibited fresh and dry root biomass gains of 123% and 110%, respectively, along with dry and fresh shoot biomass increases by 28% and 15%, respectively. Both high-performing SynComs also improved leaf water potential. The tested microbial consortia significantly enhanced drought tolerance and biomass accumulation across all crops. These findings demonstrate the potential of SynCom-based inoculants as low-cost, eco-friendly tools to improve crop productivity and resilience in water-scarcity prone regions.