Isotope Labeling to Study Phosphorus Uptake in the Arbuscular Mycorrhizal Symbiosis.

: Isotope labeling enables the detection and quantification of nutrient fluxes between soil and plants through arbuscular mycorrhizal (AM) fungi. Here we describe the use of radioactive isotopes, 33P and 32P, to study the uptake of P from soil by AM fungal mycelium and its transfer to the host plant through the mycorrhizal pathway.