A recently published article in `Science` scientific journal describes how plants feel when they are being eaten. When a plant is injured, it releases a message similar to a nervous system signal that is spread throughout the plant. This signal is very similar to the pain response found in humans and other animals.
When a person is injured, sensory cells in our bodies alert our nervous system to release the neurotransmitter glutamate. This neurotransmitter is a type of amino acid that also functions as a material for transmitting a formative message. It stimulates our brain to release adrenalin, which causes a reaction – fight or flight.
Plants do not have nervous systems, but the study describes their own version of the fight or flight signal when they are under attack. Plants also have the neurotransmitter glutamate. A plant that is bitten by a larva releases glutamate at the bite site. It activates a calcium wave (further signaling) through the entire plant body, which then causes the plant to release stress hormones. These protection hormones include chemicals to initialize the leaf’s repair process and toxic chemicals to repel the predator.
So plants may not feel pain in the same way that humans do, but this new discovery shows that they respond to injuries and attacks in a remarkably similar way. So next time you sit down to enjoy a nice salad try not to think of all the glutamate that the plants released in response to their picking.