Tomatoes warn each other against pests

Tomatoes warn and protect each other from enemies

01.05.014

Tomatoes are not only healthy, but apparently also helpful plants. As Japanese researchers have discovered, tomato plants warn each other against pests and send their neighbors protection at the same time.

Plants warn and protect each other
It has long been known that some plants, such as tobacco or corn, can warn each other against pests and at the same time send protection. In insect attacks, for example, chemicals are released that stimulate their conspecifics in the area to intensify the production of antibodies. However, it has remained unclear how exactly this early warning system works. Japanese scientists have now examined this more closely for tomato plants that were strictly isolated. A slight air flow brushed partly over plants on which the Asian cotton worm (Spodoptera litura) was amicable and also on plants without insect infestation. The Asian cotton worm is the larva of a small butterfly from the family Eulenfalter.

Tomatoes provide other plants with a raw material for their defense
Kenji Matsui and his associates from Yamaguchi University came to the conclusion that tomato plants warn each other of predators and provide their neighbors with the precursor for a repellent. The leaves of the tomato plants that were in the airflow of the affected conspecifics were found increased proportion of the chemical (z) -3-hexenyl-vicianoside (HexVic). Like the researchers in the trade magazine“Proceedings of the National Academy of Sciences“ („PNAS“), the chemical is known to inhibit the growth of butterfly larvae. The air coming from the infested plants additionally contained as its main component a chemical precursor of HexVic. Therefore, the scientists conclude that tomato plants not only emit chemical alerts, but even provide other plants with a raw material for their defense. Tomatoes are not only healthy thanks to the minerals and vitamin C they contain, but they are obviously also helpful.

Corn attracts enemies of enemies
Such chemical-based warning signals have already been demonstrated by researchers in various crops, such as tobacco or corn. So maize leaves in the attack of pests from volatile substances in their environment, with which they attract on the one hand enemies of the attacking insects and on the other hand alert neighboring plants. As a result, the warned maize plants produce a protective acid that otherwise only reacts to external injuries. This was the result of a study published last January „PNAS“ has been published. (Sb)