It has always been believed that plants are the foundation of any diet. And the more plants eaten by animals or humans, the better for their health. It turned out that this is not the case.
Biologists have discovered that plants can warn each other about the appearance of herbivores. Better than others, this feature is developed in wormwood, which recognizes its "relatives".
Richard Karban from the University of California and Kaori Shioyiri from Kyoto University (Japan) were able to confirm that wormwood can warn neighboring bushes about being eaten by grasshoppers. Scientists have also found that this warning is well understood only by close "relatives", that is, bushes that are obtained by propagation by cuttings from a common parent.
In order not to chew, you must become inedible
Scientists have known for a long time that plants can transmit signals. For example, ragweed roots, when in contact with the roots of other plants, inhibit their growth, but do not affect each other's growth. As for wormwood, back in 2003, Karban and his colleagues discovered that it could take protective measures against grasshoppers by producing a substance that makes the leaves inedible to insects.
Moreover, then biologists found out that the eaten plant releases volatile substances into the air, which are captured by the neighbors. Wormwood, for example, "smelling" such a smell, immediately begins to develop its own protective enzyme.
Such "communication" of plants does not require the presence of a nervous system, mobility or special organs of speech or other manifestations of the psyche and does not indicate the presence of emotions in plants. Scientists emphasize that there is nothing unique about the exchange of signals in plants: bacteria are also capable of this. However, scientists made one discovery, which is no longer so trivial: they found out that wormwood recognizes its "relatives"! (How "recognition" and information transfer from plant to plant occurs can be learned by studying the mechanism of action of protective psi-fields.)
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Clone warns clone
The researchers took a wormwood bush and propagated it by cuttings. Usually, wormwood does not reproduce like that, but scientists had their own goal: they wanted to get bushes that are not genetically different from each other. Bushes grown from cuttings from the same "parent" turn out to be, in fact, clones, with exactly the same cells. Biologists have suggested that this circumstance may affect the recognition of "relatives" of the alarm signals emitted by a bush that has been attacked by a pest.
The assumption turned out to be correct. If nearby grasshoppers began to eat a “relative”, the wormwood bush with the help of an enzyme made its leaves unfit for food much faster than if an arbitrary, alien bush of the same species was attacked nearby. The reaction to gnawed "relatives" was as strong as when the plant itself was eating leaves: the relationship between "relatives" was not unique to the animal world.
From evolution to field protection
Biologists consider family ties to be one of the most important driving forces of evolution. This is due to the fact that the prevention of "relatives" allows you to increase the number of genes passed on to descendants. Species that develop this recognition have a better chance of spreading their genetic material. Scientists emphasize that the benefits of discovering the ability of plants to communicate are not limited to understanding evolutionary processes.
Since grasshoppers are a kind of analogue of agricultural pests, the study of protective mechanisms that, for example, eaten wormwood produces, can lead to the development of new methods of protecting useful crops from pests.