The symbiosis with arbuscular mycorrhizal fungi contributes to plant tolerance to serpentine edaphic stress
Abstract
Based on a reciprocal transplant experiment, we evidenced the edaphic differentiation and higher tolerance of both Knautia arvensis plants and arbuscular mycorrhizal fungi of serpentine origin to serpentine soil. The serpentine isolate of arbuscular mycorrhizal fungus not only developed higher root colonisation in serpentine conditions, but it was also more efficient in the growth promotion of and phosphorus uptake by the serpentine plants.
As it had only a slight impact on magnesium uptake and no influence on calcium and nickel uptake by the serpentine plants, the improved P nutrition seemed to be the crucial mechanism of the mycorrhizal promotion effect. Our study thus proved the tolerance of a plant-mycobiont complex to specific conditions of serpentine soils, which may indicate that not only the individual components of serpentine communities but also their functional interactions are subjected to selective evolutionary forces.