The title is a quote by Charles Darwin (Book: insectivorous Plants) who was fascinated by the observations he made on this particular plant. Well, yes! Carnivory in the plant kingdom is a peculiar trait and the mysteries surrounding the same has mesmerized not only scientists but also the public in general. I have seen that something like ‘carnivorous’ plants is always met with awe and curiosity when introduced to young children who probably would only imagine something like that in the context of horror movies or science fiction. Let’s see some of the underlying mysteries that the scientists have been able to solve regarding this very real friend of ours, the Venus Flytrap!
A bit of History?
The first mention of the plant can be dated back to the mid 18th century when English botanist and a fellow of Royal Society Peter Collinson received a letter from Arthur Dobbs from North Carolina describing this unusual plant. Arthur wrote: “We have a kind of Catch Fly Sensitive which closes upon anything that touches it.”
The story continues in 1769 when a man named John Ellis, a member of the East India Company who primarily dealt with the shipping of plants, came across the Venus Fly Trap and was so stunned that he wrote a letter to eminent botanist Carl Linnaeus describing the plant. In that letter, Ellis named it Dionaea muscipula after the Greek goddess Diana (whose Roman counterpart is Venus: hence the name Venus Flytrap) and the Latin word muscipula meaning mousetrap.
Well, how does it work?
The entire process can be broken down into three stages: Luring, Capturing and Digesting. The mechanism is highly dependent on Rapid Plant Movement (something we also see in Mimosa pudica or the waterwheel plant). Like any other biological process, the actual machinery is complex and involves many steps and biochemical reactions but I will try to simplify it as far as possible.
- Luring: The reddish/fuchsia lining in the leaves and secretion of a fragrant nectar charms insects and spiders to land on the trap. They release over 50 kinds of Volatile Organic Compounds (VOCs) like terpenes, benzenoids, etc. with a fruity scent for the same purpose. Dionaea basically takes benefit of the evolutionarily conserved mode of plant-insect interaction to entice its prey.
Another interesting phenomenon that lures prey towards our friend is Fluorescence! Scientists have found out a blue glow on the inner sides of Venus flytraps when scanned at UV 366nm. Researchers then tested to see if the blue lights had any role to play in luring of the prey. In order to do this, they blocked the region of interest and waited for a few days. The plants’ prey capture success reduced severely over the 10-day period when their blue emissions were concealed.
- Capturing: There are trichomes present in the middle of the mouth of the trap/mouth which serve as the trigger for the capture. While exploring the inner trap lobes, attracted insect visitors accidentally dislocate these sensory trigger hairs, causing rapid trap closure (due to firing of action potentials (APs)). Continuing electrical stimulation causes the arrest organ to become hermetically sealed (air-tight) with the help of cilia, giving the victim no opportunity of subsequent escape.
What I found intriguing while studying this was the fact that the trichomes are so amazingly sophisticated that they can distinguish between living or non-living objects!
To balance the costs and profits of consuming insects, the plants have developed a counting system to recognize real prey from false alarms! In simple terms, for the rapid closure of the trap, there must be a minimum of 2 movements or elicitation of 2 APs.
In order to unfold the mystery behind how the flytrap distinguishes an ant from a false alarm like a drop of water, researchers applied touch stimulation and studied how the plant responded to it. In order to mimic insect prey, the scientists stimulated the hair-like sensors located on the plant’s trap. While after 2 touches, the trap closed, they found that subsequent stimuli caused touch hormone jasmonic acid (JA) signalling pathway to be activated and chemicals for nutrient absorption to be released. (Check references in case you’re interested to know more).
- Digestion: The trap is somewhat converted to a stomach after it is hermetically sealed. Jasmonic Acid signals the plant to make digestive enzymes like proteases. An acidic environment is created due to a drop in pH and the enzymes are protected by the chemical Glutathione. The process can take anything from a week to 10 days depending on the prey they’re digesting. As mentioned earlier, here too the counting mechanism plays an important role. Ideally, 5 or more stimuli are needed to activate the absorption of the products of digestion.
Some weird/interesting facts!
Now that we have talked a lot of science, let’s discuss something lighter!
Let’s start with the question, what if we feed the Dionea digest human flesh?
Honestly, I have known about the existence of this plant since school but a question of this sort had never hit my mind. Well, to answer this, under special circumstances, they have indeed shown the ability to do so. Barry Rice, an expert on carnivorous plants, had conducted the experiment when he fed the plant chunks of his own skin, he had lost due to an infection and was surprised to see that the weak digestive enzymes of the Venus Flytrap were indeed successful. To quote him, “After a week, the traps opened. I had predicted the skin chunks would be relatively inert and unaffected. After all, these were hard, crusty chunks of skin from the sole of my diseased feet. Surely the Venus flytraps would have no effect upon them.
Was I ever wrong! The skin chunks were almost completely digested. Worse, what was left no longer had much cohesion, but was gooey and slimy, like little boogers. “
Now, since Science has always been inspired from nature to solve human problems (Biomimetics). For example, Velcro was inspired from the hooks in bur fruits. I don’t know if this falls under the same umbrella but Interestingly, scientists at Seoul National University and the University of Maine have now developed robots that are modelled after the lobes of Venus flytraps, which spontaneously shut as soon as sensitive hairs inside detect a landing insect!
There are many other facets of this plant that need to be studied and understood! I hope I was able to convince you about why Darwin considered it the most wonderful plant.
You can check the references in case you want to know more. Also, the videos linked below can help you have a visual experience.
Let’s end with a question I found online. Would you like to have a Venus Flytrap in your garden? Let me know your thoughts in the comments!
Videos you can watch:
About the author: Raibat is a 4th-year Integrated MS student at the Department of Chemistry, IISER Bhopal and a KVPY fellow. Apart from being a big foodie and FCB fan, he loves trekking and camping. When he’s not sciencing, eating, or complaining about his bad luck, you will find him hooked into novels or planning his next trek! Also, he is associated with The Qrius Rhino.
Other articles by the author that you may find interesting:
- The Reason Behind Earth’s perfume!
- SOLAR POWERED SEA SLUGS!
- Something Interesting and Bizarre about Stick Insects!
- Memory transfer between two organisms! YES, you read that right!
- The Doorway Effect!
- Metals vs Microbes- the Oligodynamic Effect!
- Does hot water freeze faster than cold water? The Mpemba Effect!
- Should DHMO be banned?- The DHMO Parody!