A team of researchers in Germany has detected biomagnetic fields associated with electrical activity in a species of carnivorous plant called the Venus flytrap (Dionaea muscipula).
The Venus flytrap (Dionaea muscipula). Image credit: Conrad Erb, Science History Institute / CC BY-SA 3.0.
The bilobed trap of the Venus flytrap, formed by the modified upper part of the leaf, snaps closed within a fraction of a second when touched. Three trigger hairs that serve as mechanosensors are equally spaced on each lobe.
When a prey insect touches a trigger hair, a so-called action potential is generated and travels along both trap lobes.
If a second touch-induced action potential is fired within 30 sec, the viscoelastic energy stored in the open trap is released and the capture organ closes, imprisoning the animal food stock for digestion of a nutrient-rich meal.
“We have been able to demonstrate that action potentials in a multicellular plant system produce measurable magnetic fields, something that had never been confirmed before,” said lead author Anne Fabricant, a doctoral candidate at the Helmholtz Institute Mainz and the Johannes Gutenberg University of Mainz.
In the study, Fabricant and colleagues used heat stimulation to induce action potentials, thereby eliminating potentially disturbing factors such as mechanical background noise in their magnetic measurements.
Using atomic optically pumped magnetometers, they detected the magnetic signals with an amplitude of up to 0.5 picotesla from the Venus flytrap.
“The signal magnitude recorded is similar to what is observed during surface measurements of nerve impulses in animals,” Fabricant said.
“Our findings pave the way to understanding the molecular basis of biomagnetism in living plants,” the scientists concluded.
“In the future, magnetometry may be used to study long-distance electrical signaling in a variety of plant species, and to develop noninvasive diagnostics of plant stress and disease.”
The findings were published in the journal Scientific Reports.
A. Fabricant et al. 2021. Action potentials induce biomagnetic fields in carnivorous Venus flytrap plants. Sci Rep 11, 1438; doi: 10.1038/s41598-021-81114-w