February 21, 2021: A recent study (Scientific Reports) from Germany found that the Venus flytrap (Dionaea muscipula) plant is capable of generating small magnetic fields.
When these plants send electrical signals to trigger the closure of their traps, to catch an insect, a biomagnetism phenomenon was observed.
What are magnetic fields?
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field.
The Venus flytrap (Dionaea muscipula) is a carnivorous plant native to subtropical wetlands on the East Coast of the United States in North Carolina and South Carolina.
It catches its prey chiefly insects and arachnids with a trapping structure formed by the terminal portion of each of the plant’s leaves, which is triggered by tiny hair (called trigger hair or sensitive hair) on their inner surfaces.
When an insect or spider crawling along the leaves contacts a hair, the trap prepares to close, snapping shut only if another contact occurs within approximately twenty seconds of the first strike.
Triggering mechanism in a Venus flytrap
Triggers may occur if one-tenth of the insect is within contact.
The requirement of redundant triggering in this mechanism serves as a safeguard against wasting energy by trapping objects with no nutritional value, and the plant will only begin digestion after five more stimuli to ensure it has caught a live bug worthy of consumption.
The first author of the study Anne Fabricant explained in a release that the magnetic signals in plants are very weak and it was extremely difficult to measure them with the help of older technologies.
Using new and advanced atomic magnetometers, the team was able to measure the magnetic signals, which had an amplitude of up to 0.5 picotesla, which is millions of times weaker than the Earth’s magnetic field.
“The signal magnitude recorded is similar to what is observed during surface measurements of nerve impulses in animals,” explains Fabricant.
Interestingly, the trap is electrically excitable in a variety of ways. In addition to mechanical influences such as touch or injury, osmotic energy, for example, salt-water loads, and thermal energy in the form of heat or cold can also trigger action potentials.
The research explained that in the plant kingdom, there is a degree of electrical signaling, and it’s involved in the reception and transduction of light, temperature, touch, wounding, and chemicals.
The research also found that even though human and animal magneto physiology is a well-developed field of research, very little of the same type of work has been conducted in the plant kingdom.
In order to measure the magnetic field, the scientists used a device called an atomic magnetometer.
The discovery could be important because if the signals of other plant species can be measured, in the future, it could help with feeding us.
Farmers may be able to get data from this type of non-invasive technology by finding problems via the magnetic responses without having to damage the plants using electrodes.
Biomagnetism in plants
Though biomagnetism has been studied in humans and animals, it has not been explored much in plants and the team now aims to measure these small signals from other plant species.
They hope that this can help in identifying how the plant responds to sudden temperature changes, chemicals, and pest attacks.