New study reveals how mushrooms increase electrical communication after rainfall

Scientists have been studying the possibility of electrical signal transfer between mushrooms and across trees via the mycelial networks. It is thought that fungi generate electrical signals in response to external stimuli and use these signals to communicate with each other, coordinating growth and other behavior.

Yu Fukasawa from Tohoku University, who led the project, along with Takayuki Takehi and Daisuke Akai from the National Institute of Technology, Nagaoka College, and Masayuki Ushio from the Hakubi Center, Kyoto University (presently at the Hong Kong University of Science and Technology), said that the electrical potential began to fluctuate after raining, sometimes going over 100 mV.

The researchers correlated this fluctuation with precipitation and temperature, and causality analysis revealed that the post-rain electric potential showed signal transport among mushrooms. This transport was particularly strong between spatially close mushrooms and demonstrated directionality.

"Our results confirm the need for further studies on fungal electrical potentials under a true ecological context," said Fukasawa.

The researchers emphasized the importance of conducting further studies in the natural environment rather than in the laboratory, as many previous studies had been limited to the latter.

The new findings provide valuable insight into the complex relationships between fungi and trees in forest ecosystems. It has long been known that ectomycorrhizal fungi play a critical role in the ecological sustenance of forest trees by transferring vital nutrients to them.

However, the discovery of electrical signals between mushrooms and their possible role in coordinating growth and nutrient transfer adds a new layer of complexity to our understanding of the forest ecosystem.

In conclusion, this study is an important step forward in understanding the role of mushrooms in forest ecology. By uncovering the role of electrical signals in mushroom communication, the research provides valuable insights into the complex relationships between fungi and trees in forest ecosystems. Further studies are needed to gain a deeper understanding of the ecological context of fungal electrical potentials and their role in forest ecosystems.

Abstract

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.