Abstract Background Ecologically derived synthetic communities can provide robust plant benefits, yet generalizable rules for assembling multifunctional consortia remain limited. We hypothesized that a “top-down” community assembled from an ecological core would yield complementary functions and resilience superior to reductionist mixes. Results We distilled an eight-member, Bacillus-dominated synthetic community (hereafter referred to as SynCom) from a rice–duckweed agroecosystem by targeting taxa consistently shared across soil, root and shoot niches. Under greenhouse conditions, the SynCom concurrently promoted rice growth and suppressed sheath blight caused by Rhizoctonia solani , reducing the final disease index by 70% without detectable phytotoxicity. Leave-one-member perturbations (−Dx), combined with untargeted LC–MS profiling and qRT-PCR of biosynthetic genes, revealed a division-of-labor architecture: individual strains specialized in auxin production, siderophore-linked iron mobilization, or lipopeptide/polyketide-based antagonism. These complementary yet partially redundant contributions mapped members, metabolite pools, plant outcomes and rendered community performance resilient to single-member loss. Across −Dx contrasts, the complete SynCom uniquely recovered the full suite of plant-growth metabolites (e.g., indole-3-acetic acid, acetoin/2,3-butanediol) together with antimicrobial chemistries (e.g., surfactin, bacillomycin, fengycin, difficidin). We formalize an assembly heuristic, ecological core, complementary functions, redundancy check, that links ecological origin to predictable, multi-trait performance. Conclusions A top-down, ecology-guided route can generate a multifunction SynCom with demonstrated greenhouse efficacy and mechanistic transparency. By coupling-member perturbations with multi-omics readouts, our study provides a transferable rule for building resilient plant-associated consortia and a tractable framework for future genetic and in-plant chemical confirmations.
Song et al. (Wed,) studied this question.