Electrical potentials in the ectomycorrhizal fungus Laccaria bicolor after a rainfall event

We measured extracellular bioelectrical activities of the ectomycorrhizal basidiomycete Laccaria bicolor under field conditions to examine its response to environmental factors. Six fruit bodies of L. bicolor in a cluster, to which electrodes were attached, exhibited less electrical potentials at the beginning, probably due to the lack of precipitation for over a week. However, its electrical potential fluctuated after raining, sometimes over 100 mV. The electrical potential of the fruit bodies and its fluctuation were correlated with precipitation. Causality analysis of electrical potential after the rain showed electrical signal transport among fruit bodies, particularly between spatially close ones, with potential directionality. Our preliminary results bring a call for studies on fungal electrical potentials in a more ecological context under field conditions.

Automated summary

We measured the extracellular bioelectrical activities of Laccaria bicolor, an ectomycorrhizal basidiomycete, under field conditions to explore its response to environmental factors. Initially, the fruit bodies showed lower electrical potentials, which may be attributed to the lack of precipitation. However, after raining, the electrical potential of the fruit bodies fluctuated, sometimes exceeding 100 mV. The electrical potential and its fluctuation were correlated with precipitation, and causality analysis revealed electrical signal transport among fruit bodies, especially between spatially close ones, with potential directionality.