Membrane potential hyperpolarisation in vesicular arbuscular mycorrhizae of Allium porrum L. a non-nutritional long-distance effect of the fungus

Variations in membrane potential difference (PD) were observed between root cortical cells of Allium porrum plants, uninfected and infected with Glomus E3: cell membrane potential was constantly hyperpolarised in the latter during the time course of infection and at all degrees of infection. This hyperpolarisation persisted in the presence of an inhibitor (2,4-dinitrophenol) and of an activator (fusicoccin) of transport membrane processes, suggesting that long-distance signals generated by the fungus could be involved.