Salicylic acid, the active ingredient of aspirin, is an important plant hormone that plays a role in growth, development, photosynthesis, and disease resistance. And it could be the secret to making plants more resistant to environmental stress brought forth by the climate crisis.
Researchers have now studied how this hormone acts during stress responses. In a paper published in Science Advances, the team studied the role of the hormone in a plant called Arabidopsis, which is a member of the mustard family. They hope they can apply their findings to many other plants.
“We’d like to be able to use the gained knowledge to improve crop resistance,” Jin-Zheng Wang, Univesity of California Riverside plant geneticist and co-first author of the new study, said in a statement. “That will be crucial for the food supply in our increasingly hot, bright world.”
The Arabidopsis was exposed to environmental stresses, such as light stress. This leads to the production of reactive oxygen species or ROS. In humans, ROS can generate freckles or burns. Depending on the quantity of ROS in plants, they can either kill the plant or warn it of increasing stress.
“At non-lethal levels, ROS are like an emergency call to action, enabling the production of protective hormones such as salicylic acid,” Wang said. “ROS are a double-edged sword.”
The researchers discovered that heat, intense sunshine, or drought all lead to the formation of an alarm molecule known as MEcPP. This, in turn, leads to an increase in the production of salicylic acid. The acid is a key component in a series of defensive steps that plant cells take, including the protection of chloroplasts – the organelle in the plant cell where photosynthesis takes place.
“It’s like plants use a painkiller for aches and pains, just like we do,” said Wilhelmina van de Ven, UCR plant biologist and co-first study author.
“Because salicylic acid helps plants withstand stresses becoming more prevalent with climate change, being able to increase plants’ ability to produce it represents a step forward in challenging the impacts of climate change on everyday life,” said Katayoon Dehesh, senior paper author and UCR distinguished professor of molecular biochemistry.
“Those impacts go beyond our food. Plants clean our air by sequestering carbon dioxide, offer us shade, and provide habitat for numerous animals. The benefits of boosting their survival are exponential,” she said.
The team is now going to investigate how MEcPP comes into play with stress and how to use it to make plants more resilient as the climate crisis unfolds.