Soil legacy of arbuscular mycorrhizal fungus Gigaspora margarita: The potassium-sequestering glomalin improves peanut (Arachis hypogaea) drought resistance and pod yield

•Peanuts cultivated in the sterilized soil with AM fungi-inoculated history exhibit enhanced drought performance.•Potassium-sequestering glomalin directly contributes to the enhanced peanut drought performance.•Peanut root exudates prime the dissociation of glomalin-bound potassium.