Imagine yourself in a situation in which you and everyone surrounding you are being attacked by an unknown predator. You hear signs of chaos all around you and your fight-or-flight instincts are gearing up to protect you from impending doom. You are just about to plan your miraculous escape when you notice your feet are stuck planted to the ground, and you are incapable of fleeing the scene. What would you do to protect yourself?
While this scenario may seem unlikely for a human to encounter (What, did you forget about the tube of superglue you just smeared on the bottom of your feet?), it is something that a plant may face on a daily basis. The methods in which plants defend themselves from threatening situations vary greatly and are the focus of a study done by scientists at the University of Wisconsin-Madison in the laboratory of John Orrock and Simon Gilroy. The study is currently under review.
“If you’re a plant, one of the things that makes you interesting is that you can’t run away,” Orrock said on his lab’s work.
In their study, Orrock and Gilroy examined the defense mechanisms of black mustard plants when introduced in a variety of ways to environments with snail mucus.
The snail mucus simulated a threatening signal to the plants and, according to the study, caused the black mustard plants to become increasingly less palatable the more they were exposed to the mucus over the course of their lifetime.
Orrock compared the mustard plant’s reaction to a mouse detecting the presence of a nearby cat by smelling the cat’s urine.
“That mouse knows that there’s probably a cat around about to cause great bodily harm to said mouse,” said Orrock, “So that mouse prepares itself for that attack like the mustard plants when they make themselves less palatable after recognizing the snail slime.”
The study had several test groups and found the plants that were exposed to the snail mucus multiple times over the course of the study were more prepared for the possibility of a snail attack, as opposed to those who were only exposed while they were seeds. These findings imply the black mustard plants recognized the signs of a snail attack because of a change in their chemical structure from previous experiences.
“Amazingly, the molecular signature of plant paranoia is actually known because of this,” Orrock said.
A plant changing its chemical composition to make itself less tasty to herbivores is just one of many ways in which a plant can defend itself from harm. Other methods can include developing thorns or producing tougher leaves that are harder for predators to chew on.
“A plant can even defend itself against things that have never even attacked it yet, which is known as the ‘Whispering Tree’ effect,” Orrock said.
In this case, plants that are attacked send volatile chemicals into the air that neighboring plants pick up on and use as a cue to go into defensive mode.
While these defense mechanisms are capable of increasing a plant’s chance of survival when imposed with the snail’s terror, caterpillars and herbivores, they come at a cost.
“These defenses take up a lot of the plant’s energy that could otherwise be going into other plant functions such as growth,” Orrock said.
This is why it is important for a plant to be able to recognize cues of dangers, such as the black mustard plants reacting to the presence of snail slime. If a plant can learn to turn its defense mechanisms on and off based on whether or not the plant is in danger, it can reserve energy for use on its other demands, which maximizesthe plant’s well-being.
The next step for Orrock, Gilroy and their lab is a follow-up study in which they address further questions that have arisen from this first study, such as whether it is the frequency or quantity of slime exposure that impacts the black mustard plant’s palatability. They are also interested in mapping out which genes are turned on or off when a plant’s defense mechanisms are activated.
The hope is that they will be able to better understand how plants manage to successfully ward off danger even with the limitations of being rooted to the ground.
Imagine yourself in a situation in which you and everyone surrounding you are being attacked by an unknown predator. You hear signs of chaos all around you and your fight - or-flight instincts are gearing up to protect you from impending doom. You are just about to plan your miraculous escape when you notice that your feet are stuck planted to the ground and you are incapable of fleeing the scene. What would you do to protect yourself?
While this scenario may seem unlikely for a human to encounter (What, did you forget about the tube of superglue you just smeared on the bottom of your feet?), it is something that a plant may face on a daily basis. The methods in which plants defend themselves from threatening situations vary greatly and are the focus of a study currently under review done by scientists at the University of Wisconsin-Madison in the laboratory of John Orrock and Simon Gilroy.
“If you’re a plant, one of the things that makes you interesting is that you can’t run away,” Orrock said on the work of his lab.
In their study, Orrock and Gilroy examined the defense mechanisms of black mustard plants when introduced in a variety of ways to environments with snail mucus.
The snail mucus simulated a threatening signal to the plants and, according to the study, caused the black mustard plants to become increasingly less palatable the more they were exposed to the mucus over the course of their lifetime.
Orrock compared the mustard plant’s reaction to a mouse detecting the presence of a nearby cat by smelling the cat’s urine.
“That mouse knows that there’s probably a cat around about to cause great bodily harm to said mouse. So that mouse prepares itself for that attack like the mustard plants when they make themselves less palatable after recognizing the snail slime,” Orrock said.
The study had several tests groups and found that those plants which were exposed to the snail mucus multiple times over the course of the study were more prepared for the possibility of a snail attack as opposed to those who were only exposed while they were seeds. These findings imply that the black mustard plants were able to recognize the signs of a snail attack according to a change in their chemical structure from previous experiences.
“Amazingly, the molecular signature of plant paranoia is actually known because of this,” Orrock said.
A plant changing its chemical composition to make itself less tasty to herbivores is just one of many ways in which a plant can defend itself from harm. Other methods can include developing thorns or producing tougher leaves that are harder for predators to chew on.
“A plant can even defend itself against things that have never even attacked it yet which is known as the “Whispering Tree” effect,” Orrock said.
In this case, plants that are attacked send out volatile chemicals into the air that neighboring plants pick up on and use as a cue to go into defensive mode.
While these defense mechanisms are capable of increasing a plant’s chance of survival when imposed with the terrors of snails, caterpillars, and herbivores, they come at a cost.
“These defenses take up a lot of the plant’s energy that could otherwise be going into other plant functions such as growth,” Orrock said.
This is why it is important for a plant to be able to recognize cues of dangers, such as the black mustard plants reacting to the presence of snail slime. If a plant can learn to turn its defense mechanisms on and off according to whether or not the plant is in danger, it can reserve energy for it to use on its other demands which maximizes the plants well-being.
The next step for Orrock, Gilroy, and their lab is a follow-up study in which they address further questions that have arisen from this first study such as whether it is the frequency of slime exposure or the quantity that impacts the black mustard plants palatability. They are also interested in mapping out which genes are turned on or off when a plant’s defense mechanisms are activated.
The hope is that they will be able to better understand how plants manage to successfully ward off danger even with the limitations of being rooted to the ground.
