Plant perception (physiology)
[1] Botanical research has revealed that plants are capable of reacting to a broad range of stimuli, including chemicals, gravity, light, moisture, infections, temperature, oxygen and carbon dioxide concentrations, parasite infestation, disease, physical disruption, sound,[2][3][4][5] and touch.
The internal clock coupled with the ability to perceive light also allows plants to measure the time of the day and so determine the season of the year.
If the light is very bright or if the levels of harmful ultraviolet radiation increase, plants produce more of their protective pigments that act as sunscreens.
[8] Studies on the vine Boquila trifoliata has raised questions on the mode by which they are able to perceive and mimic the shape of the leaves of the plant upon which they climb.
These responses are generally slow (on the order of multiple hours), and can best be observed with time-lapse cinematography, but rapid movements can occur as well.
For example, the so-called "sensitive plant" (Mimosa pudica) responds to even the slightest physical touch by quickly folding its thin pinnate leaves such that they point downwards,[16] and carnivorous plants such as the Venus flytrap (Dionaea muscipula) produce specialized leaf structures that snap shut when touched or landed upon by insects.
In the Venus flytrap, touch is detected by cilia lining the inside of the specialized leaves, which generate an action potential that stimulates motor cells and causes movement to occur.
[18] Plants upregulate chemical defenses such as glucosinolate and anthocyanin in response to vibrations created during herbivory.
Plants produce several signal molecules usually associated with animal nervous systems, such as glutamate, GABA, acetylcholine, melatonin, and serotonin.
These electrophysiological ions bind to receptors on the receiving cell causing downstream effects result from one or a combination of molecules present.
This means of transferring information and activating physiological responses via a signaling molecule system has been found to be faster and more frequent in the presence of APs.
[26] These action potentials can influence processes such as actin-based cytoplasmic streaming, plant organ movements, wound responses, respiration, photosynthesis, and flowering.
For example, they can produce a slew of different chemical toxins against predators and parasites or they can induce rapid cell death to prevent the spread of infectious agents.
