Plant immunity; more discoveries (Introduction)

by David Turell , Monday, August 24, 2020, 18:30 (1343 days ago) @ David Turell

How tobacco plants protect again weevils:

https://phys.org/news/2020-08-strigolactones-tolerance-weevils-tobacco.html

"Not only animals, but also plants have different hormones that control various processes in the body. One class of these signaling substances that were only recognized as hormones quite recently are strigolactones. In plants, they are involved in shoot formation inhibit further branching of the stem. As scientists at the Max Planck Institute for Chemical Ecology have now discovered, a change in the signaling pathway of strigolactones influences processes regulated by other plant hormones, and—as a consequence—a plant's defense against herbivores.

***

"The results of the study demonstrate that although strigolactones do not directly regulate defenses against the weevil, they indirectly use the existing hormonal regulatory networks, here via jasmonates and auxins, to produce defensive substances that enable the plant to tolerate this herbivore inside its stem.

"'In short, 'defenses' damage the herbivores, while 'tolerance' traits decrease the damage that herbivore attack causes. It is in the realm of tolerance traits that makes the discovery that these hormones fine-tune plant defense via their crosstalk with other hormones, such as jasmonates and auxins, so exciting," says Ian Baldwin, director of the Department of Molecular Ecology where the investigations have been carried out.

"The researchers propose that strigolactones in the plant represent a kind of switch between defense against and tolerance of herbivores, a hypothesis that—if confirmed—would also offer new interesting approaches for plant breeding."

Comment: Complex defenses with several different proteins require design to put such a system together, and must be present at the start of the life of the specific plant type.