It turns out that the secret of the pest that silences the tomato's 'cry for help' lies in 'saliva'



Plants have no eyes, mouth, or limbs, but many species have the means to seek help or alert their surroundings when attacked by a foreign enemy.

A research team at Penn State University reported the results of an experiment in which 'pest saliva' is the secret to keeping pests eating leaves while disabling the tomato's defensive response, 'screaming for help.'

Silencing the alarm: an insect salivary enzyme closes plant stomata and inhibits volatile release --Lin ---- New Phytologist --Wiley Online Library
https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.17214


'Like a horror movie': Caterpillar silences tomato's cry for help, scientists find
https://phys.org/news/2021-02-horror-movie-caterpillar-silences-tomato.html


Past studies have shown that plants react in some way when exposed to stress. For example, it has been found that a type of sweet potato uses an odorant to inform it when it is attacked by an enemy.

There is a variety of sweet potatoes that conveys enemy attacks to other sweet potatoes by 'smell' --GIGAZINE



In addition, experimental results have also been announced that when tomatoes and tobacco are subjected to stress such as water shortage or physical damage, ultrasonic waves are emitted.

Studies show that stressed plants are making 'ultrasonic screams'-GIGAZINE



In addition, tomatoes have been shown to release plant volatile chemicals (HIPV) when their leaves are bitten by insects, attracting bees to plant eggs in the insects. A research team at Pennsylvania State University describes this release of HIPV as a 'cry for help.'

However, tomato feeding damage by pests continues to be a major problem for farmers, so while tomatoes have protective measures against insects, insects also release HIPV to survive. It is possible that you have the means to disable it. Nevertheless, little was known about the mechanism by which insects nullify HIPV.

The research team focused on the larvae of the corn earworm (scientific name: Helicoverpa zea) to explore the secrets of this mechanism.

Corn earworm larvae are designated as specific important pests (PDF file) because they devour various crops such as tomatoes, tobacco, corn, and green peppers and cause serious damage. The researchers suspected that glucose oxidase in the saliva of corn earworm larvae depletes the glucose levels in the stomata on the surface of the plant, preventing them from opening and preventing the release of HIPV.



Therefore, the research team prepared two types of larvae, one with glucose oxidase in saliva and the other without glucose oxidase, using the gene editing technology CRISPR-Cas9. Each larva was fed a tomato leaf and the release of HIVV was detected. The results showed that larvae that did not contain glucose oxidase in saliva could not stop the release of HIPV.

Professor Gary Felton, a professor of entomology at Penn State University, said, 'Corn earworm larvae live throughout the United States and also damage corn, cotton, soybeans, and strawberries. Based on the results of this study. Therefore, it may be possible to take preventive strategies such as improving the varieties so that they are less affected by glucose oxidase. '

In addition, the research team led by Professor Felton is investigating whether the same phenomenon occurs in other types of larvae.

in Science,   Creature, Posted by log1i_yk