(ORDO NEWS) — You’re probably reaching for painkillers for headaches, and plants seem to do something similar: in stressful situations due to the dangers surrounding them, plants are able to produce their own aspirin.
The new study takes a closer look at this particular plant self-defense mechanism, as well as how the production of aspirin’s active metabolite, salicylic acid, is regulated.
While salicylic acid has been used by humans for centuries as a remedy for pain and inflammation, in plants it plays a fundamental role in signaling, regulating and protecting against pathogens.
Produced in chloroplasts (tiny green organelles where photosynthesis takes place), it is usually produced in response to stress.
“It’s like plants using a painkiller for pain, just like we do,” says plant biologist Wilhelmina van de Ven of the University of California, Riverside (UCR).
To better understand the complex chain of reactions that plants perform in a stressful situation, Van de Ven and her team conducted a biochemical analysis of plants mutated to block key stress signaling pathways.
Environmental stresses cause the formation of reactive oxygen species (ROS) in all living organisms. One example that you may be familiar with is sunburn on your skin if you are in direct sunlight for too long without sunscreen.
In the case of plants, these stresses include unfriendly insects, drought, and excessive heat. While high levels of ROS in plants can be lethal, smaller amounts serve an important protective function – and so their regulation is key.
The researchers used rockcress or Arabidopsis as a model plant for experiments. They focused on an early warning molecule called MEcPP, which has also been found in bacteria and malaria parasites.
It appears that when MEcPP accumulates in a plant, it causes a chemical reaction and a backlash that includes salicylic acid.
This knowledge could help us modify plants in the future to be more resistant to environmental hazards.
“At non-lethal levels, ROS are like an emergency call to action, allowing the production of protective hormones such as salicylic acid,” says plant geneticist Jin-Zheng Wang of UCR. “ROS is a double-edged sword.”
“We would like to be able to use the knowledge gained to improve crop resilience. This will be critical to food security in our increasingly hot, vibrant world.”
There’s still a lot we don’t know about the MEcPP molecule and its function, but understanding how this mechanism works could help scientists use it to their advantage: produce plants that are better able to cope with stresses and strains.
We know that plants, like animals, are under increasing pressure from a warming climate, and it is unclear how many species could survive if average temperatures continued to rise.
As the researchers note, the stresses examined in this study – the response to high temperatures, constant sunlight and lack of water – are all experienced by plants in the world right now … and, of course, if plants are in trouble, so are we.
“This impact goes beyond our food,” says molecular biochemist Katayoun Dehesh of UCR.
“Plants clean our air by absorbing carbon dioxide, give us shade and provide habitat for numerous animals. The benefits of increasing their survival rate are exponential.”
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