Rhizophagus intraradices improves soybean microbiome niche under saline-alkaline stress across critical growth stages

ABSTRACT:

Background

Soil salinization and alkalization severely threaten soybean growth and yield. Arbuscular mycorrhizal fungi (AMF), specifically Rhizophagus intraradices (Ri), enhance stress tolerance and soil quality, yet their mechanisms in regulating microbial-metabolite interactions during critical soybean growth stages remain unclear.

Results

This research employed partitioned (rhizosphere and hyphosphere) pot experiments in natural saline-alkaline soil, integrating high-throughput sequencing and untargeted metabolomics to analyze Ri effects on microbial communities and metabolic functions at branching (V5), pod development (R4), and mature pod (R8) stages. Results revealed V5 stage for Ri to activate host resistance, R4 for hyphal expansion (density 21.13 m/g), enhancing nutrient uptake, and R8 stage for increased spore and glomalin-related soil protein (GRSP) secretion to alleviate stress. Ri differentially regulates bacterial-fungal networks, enriching biomarker and driving stochastic microbial assembly. Ri shifted bacterial assembly toward stochasticity and enriched biomarkers. Bacterial richness peaked under RiRR4 (+Ri, R4 rhizosphere; +27.06% vs CRR4). Fungal assembly showed a different trend, peaking under RiRV5 (+Ri, V5 rhizosphere; +39.75% vs CRV5). Ri enhanced plant resistance and soybean growth via bacterial diversity in rhizosphere soil. Metabolomics identified phenylalanine metabolism as a core Ri-regulated pathway under saline-alkaline stress, facilitating carbon-nitrogen cycling and secondary metabolite accumulation.

Conclusions

This research reveals how Ri coordinates microbial and metabolic processes to enhance saline-alkaline resistance in soybean.

INSTRUMENT(S): Liquid Chromatography MS - positive - hilic, Liquid Chromatography MS - negative - hilic

PROVIDER: MTBLS13661 | MetaboLights | 2026-01-12

REPOSITORIES: MetaboLights