The fearsome botanical carnivore known as the Venus flytrap utilizes ancient defenses against herbivores, but turns them up to eleven to flip the script and become predators instead of prey, according to new research published online in the journal Genome Research.
As part of their study, biophysicist Rainer Hedrich and bioinformaticist Jörg Schultz of the Julius Maximilian University of Würzburg in Germany monitored the various genes that Venus flytraps (Dionaea muscipula) expressed when they sensed, captured, and then consumed their prey.
According to Science, Hedrich and Schultz were testing the hypothesis that the plants developed their predatory mechanisms by weaponizing behaviors typically used to detect insects and defend against these invaders, enabling them to survive by providing an alternate source of nutrition.
“We show that the transcriptomic landscape of the Dionaea trap is dramatically shifted toward signal transduction and nutrient transport upon insect feeding, with touch hormone signaling and protein secretion prevailing,” the duo wrote. “At the same time, a massive induction of general defense responses is accompanied by the repression of cell death–related genes/processes.”
So… what exactly does that mean?
By monitoring the behavior of Venus flytraps, the study authors found that it takes advantage of an alarm system that alerts the planet when its would-be victim makes contact with a certain type of hair. This hair essentially acts like a tripwire, sending electrical impulses that stimulate glands in the plant and cause it to produce a substance known as jasmonic acid.
This acid, Science explained, is used by other plants as a defense against herbivores. While they have a different purpose, the two different kinds of plants share similar gene expression patterns, said Hedrich. However, that’s where the similarities end, the researchers explained.
In noncarnivorous plants, jasmonic acid results in the synthesis of defense toxins and molecules that inhibit hydrolase, a substance which is used by herbivores to break down proteins found in the plant. Meanwhile in the Venus flytraps, digestive enzymes engulf the attacker and allow the plant to absorb nutrients, and while both types of plants produce their own hydrolases, flytraps do so at a much higher rate to break down their attacker and turn it into a source of food.
Thus, they hypothesize that the Venus flytrap evolved its carnivorous nature by adapting ancient defense mechanisms and molecular pathways, taking what had been a way for a planet to protect itself and turning it into a method for nutrient acquisition. The genes expressed by Dionaea traps as it athers nutrients are similar to those used by the roots of other plants, they told Science.
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