ENTHRALLING PLANTS: Venus Flytraps

FLORA FERN

By Abrar Hasanat

Venus flytraps are one of the most fascinating and amazing species of plants out there (albeit based on visual representation, some might not agree with it).  Venus flytraps, in contrast to most plants, are carnivorous, meaning they feed on animal flesh.₁ The Venus flytrap is "one of the most amazing [plants] in the world," according to Charles Darwin in his 1875 book "Insectivorous Plants."₂ This conclusion was reached without a doubt after witnessing this plant's jaws close around an insect, catching it for a meal.

When most people think of carnivorous plants, they imagine the Venus Flytrap with its jaw-like feeding mechanism. However, scientists now identified another peculiar property: it creates a detectable magnetic field! But, how does this actually work? And how do flytraps catch their prey in the first place? Today we will discuss in detail how these plants acquire nutrients and how they produce magnetic fields.

How Do Venus Flytraps Consume Food

Before we get into how these intriguing plants generate magnetic fields, let's talk about how they absorb nutrition. Regardless of whether you've seen "The Little Shop of Horrors," you've undoubtedly seen Venus flytraps, also known as Dionaea Muscipula. They're a  carnivorous plant, identified by their pinkish mouth pads and interlocking teeth.₃ One frequent myth is that flytraps solely consume flies; however, they also devour ants and spiders in their natural environments in the Carolinas. Flytraps, like other plants, convert energy through photosynthesis. But still, they rely on insect consumption of nitrogen and phosphate to compensate for the nutritional deficiency of the soil in which they grow.₄

When an insect enters the flytrap's mouth, the three trigger hairs on each of the two pads are activated. This trigger generates an electrical pulse, and the insect has approximately 30 seconds to flee. If the insect sets off yet another hair, the flytrap will immediately close its leaf pads and trap the insect. The plant will shut even more tightly as the beetle struggles to escape. Digestive fluids eventually move into the mouth region and break down the insect. After a week, all that is left is the exoskeleton of the bug, which the flytrap releases.₅

So, now that we know how they get their nutrition, the next big question is - 

What Scientists Have Discovered

A study conducted in 2011 used atomic magnetometers, which are sensitive enough to detect extremely minute changes, to try and identify a magnetic field around a Titan arum (Amorphophallus titanium), a big and pungent plant.  The experiment was deemed unsuccessful because the analysis showed that the plant produced no magnetic field stronger than a millionth of the intensity of the magnetic field encircling our planet. Participants in the 2011 study stated that if they were to take any more action, it would require studying a smaller plant.₆,₇

Later, in early 2021, using a much more sophisticated atomic magnetometer, which can deduce a shift in magnetic fields from the spin of electrons, scientists in Berlin discovered magnetic signals from a Venus flytrap. They found signals as high as 0.5 pico-tesla when the flytrap's "jaws" closed, which is on par with the strength of animal nerve impulses.₈

Let’s put that value in perspective:

It's been calculated that the magnetic field of a toaster is 300,000 times stronger than that of the human brain; the magnetic field of the Earth is 2,000 times stronger than that of a toaster; again, the magnetic pull of a refrigerator is 58 times stronger than that of Earth's field. That's why it took researchers so long to notice plant signals; the one we just picked up from a Venus flytrap is a billion times weaker than a fridge magnet.₉,₁₀

So, now a new question arises: 

How Do Venus Flytraps Show Biomagnetism

According to the principles of biomagnetism, any object carrying an electric current must produce a magnetic field. The electric impulses, known as action potentials, are presumably the source of the Venus flytrap's magnetic field, which causes the leaves to close. Insects can set off an action potential by touching one of the trigger hairs on the carnivorous plant's trap.₁₁

Biomagnetism in both animal and human brains has been the subject of scientific investigation to understand, modulate and image the communication between the brain and nervous system. In that sense, it can be said that sometimes this plant even works like a brain. Since plants lack nerves but are nonetheless capable of transmitting electrical impulses, this is a rare phenomenon. A Venus flytrap's trap can close in response to action potentials generated by mechanical, thermal, chemical, or electrical stimuli. For their study, physicist Anne Fabricant and her team heated a flytrap to activate its action potential. The magnetic field of the flytrap was then measured by her team using a highly sensitive magnetometer.₈

Alright, so now that we’ve learned how these work and why they work, you might wonder

Why Does This Matter?

Well, this is a major step forward in our understanding of how plants talk to one another. Very few magnetic fields have been found in plants thus far. Algae and bean plants have also been shown to emit magnetic fields by scientists in the past, but they were really insignificant.₁₂ The researchers had no doubt that they would find the magnetic field, but the problem was determining how to detect it. They had to see it in a magnetically silent room because the magnetic field was weak. But with the Venus Flytrap experiment, it was possible rather easily.₈

Moreover, scientists are now keen to look into the possible magnetic fields of other plants as a result of this flytrap experiment. The use of an atomic magnetometer in this work is extremely critical: not only does it operate at room temperature, but it is also portable and compact. Understanding this technological advancement in the future could lead to noninvasive monitoring and diagnosis of plant stress and disease. Scientists can better understand crop plant reactions to climate, pests, and pesticides if they can analyze plant electrical signals.₁₃

Conclusion: 

The Venus flytrap has long been an intriguing plant due to the manner in which it obtains nutrients — that is, by eating bugs, more or less. The notion that we now have the ability to identify its magnetic field is a significant breakthrough in the field of plant communication. We wouldn't be shocked if the infamous flytrap appears in even more innovative investigations in the future! 

Works Cited

1. Pennisi, Elizabeth. “How Venus Flytraps Evolved Their Taste for Meat | Science | AAAS.” Science. American Association for the Advancement of Science, May 14, 2020. https://www.science.org/content/article/how-venus-flytraps-evolved-their-taste-meat.

2. Gibson, Thomas C., and Donald M. Waller. “Evolving Darwin's ‘Most Wonderful’ Plant: Ecological Steps to a Snap‐Trap.” New Phytologist 183, no. 3 (2009): 575–87. https://doi.org/10.1111/j.1469-8137.2009.02935.x.

3. Bradford, Alina. “Facts about Venus Flytraps.” LiveScience. Future US Inc, February 25, 2017. https://www.livescience.com/58021-venus-flytrap-facts.html#:~:text=Venus%20flytraps%20grow%20to%20around,shut%2C%20they%20form%20a%20trap.

4. “Venus Fly Trap (Dionaea Muscipula): U.S. Fish & Wildlife Service.” U.S. Fish & Wildlife Service. Accessed October 1, 2022. https://www.fws.gov/species/venus-fly-trap-dionaea-muscipula.

5. Malec, Jackson. “University of Notre Dame.” Biomechanics in the Wild. University of Notre Dame, September 30, 2022. https://sites.nd.edu/biomechanics-in-the-wild/2022/05/03/secrets-of-the-rapid-snapping-mechanism-of-a-venus-fly-trap/?utm_source=rss&utm_medium=rss&utm_campaign=secrets-of-the-rapid-snapping-mechanism-of-a-venus-fly-trap.

6. Corsini, Eric, Victor Acosta, Nicolas Baddour, James Higbie, Brian Lester, Paul Licht, Brian Patton, Mark Prouty, and Dmitry Budker. “Search for Plant Biomagnetism with a Sensitive Atomic Magnetometer.” Journal of Applied Physics 109, no. 7 (2011): 074701. https://doi.org/10.1063/1.3560920.

7. UCBerkeley. “If Plants Generate Magnetic Fields, They're Not Sayin'.” EurekAlert! American Association for the Advancement of Science, April 7, 2011. https://www.eurekalert.org/news-releases/553499.

8. Fabricant, A., Iwata, G.Z., Scherzer, S. et al. Action potentials induce biomagnetic fields in carnivorous Venus flytrap plants. Sci Rep 11, 1438 (2021). https://doi.org/10.1038/s41598-021-81114-w

9. A. Fabricant et al., Action potentials induce biomagnetic fields in carnivorous Venus flytrap plants, Scientific Reports 11: 1438, 14 January 2021, DOI: 10.1038/s41598-021-81114-w

10. Campion, Thobey. “Venus Flytraps Have Magnetic Fields like the Human Brain.” VICE. Vice Media Group, March 19, 2021. https://www.vice.com/en/article/xgzb4k/venus-flytraps-have-magnetic-fields-like-the-human-brain.

11. Rayne, Elizabeth. “Venus Flytraps Just Got More Terrifying Because They Generate Magnetic Fields with Their Vicious Jaws.” SYFY. SYFY Media, LLC, February 9, 2021. https://www.syfy.com/syfy-wire/venus-flytraps-generate-magnetic-fields.

12. Lewandowska, Sylwia, Michalak, Izabela, Niemczyk, Katarzyna, Detyna, Jerzy, Bujak, Henryk and Arik, Pelin. "Influence of the Static Magnetic Field and Algal Extract on the Germination of Soybean Seeds" Open Chemistry 17, no. 1 (2019): 516-525. https://doi.org/10.1515/chem-2019-0039

13. Fox, Alex. “Magnetic Fields Detected in Venus Flytraps.” Smithsonian Magazine. Smithsonian Institution, February 10, 2021. https://www.smithsonianmag.com/smart-news/magnetic-fields-detected-venus-flytraps-180976967/.