Action potentials induce biomagnetic fields in Venus flytrap plants

TL;DR

This study demonstrates that electrical action potentials in Venus flytrap plants generate detectable biomagnetic fields, opening new avenues for noninvasive plant diagnostics and understanding plant electrophysiology.

Contribution

First demonstration of biomagnetic fields associated with action potentials in Venus flytrap plants using atomic magnetometers.

Findings

APs induce measurable magnetic signals in Venus flytrap

Magnetic signals mirror the temporal profile of electrical APs

Potential for noninvasive diagnostics of plant health

Abstract

Upon stimulation, plants elicit electrical signals that can travel within a cellular network analogous to the animal nervous system. It is well-known that in the human brain, voltage changes in certain regions result from concerted electrical activity which, in the form of action potentials (APs), travels within nerve-cell arrays. Electrophysiological techniques like electroencephalography, magnetoencephalography, and magnetic resonance imaging are used to record this activity and to diagnose disorders. In the plant kingdom, two types of electrical signals are observed: all-or-nothing APs of similar amplitudes to those seen in humans and animals, and slow-wave potentials of smaller amplitudes. Sharp APs appear restricted to unique plant species like the "sensitive plant", Mimosa pudica, and the carnivorous Venus flytrap, Dionaea muscipula. Here we ask the question, is electrical activity in the Venus flytrap accompanied by distinct magnetic signals? Using atomic optically pumped magnetometers, biomagnetism in AP-firing traps of the carnivorous plant was recorded. APs were induced by heat stimulation, and the thermal properties of ion channels underlying the AP were studied. The measured magnetic signals exhibit similar temporal behavior and shape to the fast de- and repolarization AP phases. Our findings pave the way to understanding the molecular basis of biomagnetism, which might be used to improve magnetometer-based noninvasive diagnostics of plant stress and disease.