Chilling-induced restructuring of seed-borne endophytes enhances early cold tolerance and microbiome assembly in common vetch

ABSTRACT: Chilling stress constitutes a major abiotic constraint on plant growth and productivity. Although plants mobilize well-characterized physiological and transcriptional acclimation mechanisms, the integrative roles of root-associated microbiomes and root exudate chemistry in chilling tolerance, particularly in leguminous systems, remain incompletely resolved. Results In Vicia sativa, chilling induced transient physiological adjustments and system-wide transcriptomic reprogramming, with pronounced enrichment of genes associated with MAPK-mediated stress signaling and hormone transduction pathways. The endophytic bacterial community underwent marked restructuring, resulting in a root-enriched assemblage of chilling-associated taxa, notably Pseudomonas and members of the Allorhizobium–Neorhizobium–Pararhizobium–Rhizobium (ANPR) clade. Two chilling-enriched endophytes isolated from this system—Pseudomonas endophytica R9 and Rhizobium sp. R17—displayed complementary plant growth-promoting (PGP) traits. Co-inoculation with this consortium most effectively mitigated chilling-induced growth suppression, enhanced photosynthetic performance, and recalibrated phytohormone profiles, increasing jasmonic acid (JA) and abscisic acid (ABA) while reducing salicylic acid (SA) and cytokinin (CTK) concentrations. Inoculation further reshaped rhizosphere–endosphere microbiome assembly, promoted microbial recruitment from soil into root tissues, and increased ecological network complexity. Root exudate metabolomics revealed selective enrichment of antimicrobial metabolites whose abundance correlated with microbiome restructuring and suggested activation of a JA-mediated induced systemic resistance (ISR) pathway. This study demonstrates that chilling-enriched endophytes contribute to chilling tolerance in V. sativa through a coordinated mechanism involving root exudate reprogramming, microbiome reassembly, and activation of a JA-centered ISR pathway. The combined Pseudomonas–Rhizobium consortium described here represents a tractable microbial strategy for enhancing resilience in forage legumes under chilling stress.

INSTRUMENT(S): Liquid Chromatography MS - alternating - reverse-phase

PROVIDER: MTBLS14339 | MetaboLights | 2026-04-21

REPOSITORIES: MetaboLights