Plants have a chemical communication that occurs, for example, when attacking phytophagous insects, then and as a result of the bite, the plant emits a molecule that acts as a neurotransmitter and makes other plants adopt preventive measures, defense measures . That does not mean that plants have a brain or will to control that communication. But there is a chemical communication that is also very efficient.
It is essential to understand very well that in plants there is nothing like a brain or a nervous system that controls these communications and that these do not have any kind of voluntariness on the part of the plants. That is, the plants do not decide when they emit those communications; what happens is that some situations trigger in them chemical processes that are detected by other plants in which, in turn, these molecules trigger new processes that protect the individuals that receive them. For example, in some cases when an insect attacks a plant by contact, it emits a molecule detected by other plants in its environment that causes them to shrink and thus protect against future attack.
When an insect attacks a plant by contact, it emits a molecule detected by other plants in its environment that causes them to shrink and thus protect against future attack
A very curious thing is that for some signal of defense against insects, the chemical molecule that acts as a warning is a glutamate, the same molecule that acts for similar effects in animals. That is to say that although in the case of plants the chemical communication system is automatic, the amino acid they emit is the same that animals produce in similar situations to communicate with each other.
This chemical communication is usually between individuals of the same species but those molecules that emit can also be recognized by plants of other species. This is very interesting because we are not talking about the protection of an isolated species, we are talking about communication in an ecosystem. And that means that this type of communications can also be very efficient for the defense of the global ecosystem. This is a line of recent research that is being given a lot of attention because it talks about the global defense of the ecosystem.
In addition to these chemical communications before the attack of insects or other pests that can infect the plants and that are investigations that have taken much importance in the last years there are other types of communication between the plants that we know much longer ago. Perhaps the most important of these is the one that allows cross-pollination to occur, that is, it avoids self-fertilization and the genetic problems that this can produce. This is solved by some plant species with maturation of stamens and ovaries at different times. For example, in a plant the stamens are developed first and the ovary is kept undeveloped but in the opposite one, the ovary has first developed so that the pollen from the first one can reach it and produce its fertilization. It is as if they agreed. The vegetal world is very rich in this type of communications that are totally chemical processes, many are made by pheromones and others by biological roads of controlled development.
Ana Crespo She is a botanist, academic of the Royal Academy of Exact Physical and Natural Sciences and Professor Emeritus of the Complutense University of Madrid.
Question asked via email Isabel Fernández
Coordination and writing: Victoria Toro