Plants Can Self-Medicate By Producing Own Aspirin When Stressed

When people experience headaches and sore muscles, they often reach for painkillers; similarly, plants have been seen to do something similar. When under the stress of various hazards in their surroundings, plants can also self-medicate with their own aspirin.

Plant Self-Defense: Stress and Regulation

(Photo: Alejandro Barron by Pexels)

A recent study published in the Plant Sciences, titled "Reciprocity between a retrograde signal and a putative metalloprotease reconfigures plastidial metabolic and structural states," analyzes a plant self-defense mechanism that allows them to produce the active metabolite of aspirin - salicylic acid, and how it is regulated.

Although salicylic acid has been used for centuries in treating human pain and inflammation, it plays a vital role in plant signaling, regulation, and pathogen defense.

Produced in the plant's chloroplasts, minuscule green organelles where photosynthesis is carried out, it is typically generated by plants in response to stress. Wilhelmina van der Ven, the study's co-author and a plant biologist from the University of California Riverside, says that plants use painkillers for pains and aches, similar to humans.

To understand further the complex chain reactions plants undergo when under stress, can der Ven and her colleagues performed biochemical analysis on plants mutated to block the effects of vital stress signaling pathways.

Environmental stresses create reactive oxygen species in all organisms. An example is sunburnt skin when exposed to prolonged exposure to direct sunlight.

These stresses include drought, unfriendly insects, and excessive heat for plants. Although high levels of ROS in plants can be lethal, smaller amounts have a vital safety function - hence regulation is necessary.

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Analysing Plant Self-Medication

For the study, researchers utilized Arabidopsis or Rockcress as the plant model for experiments. The team focused on an early warning molecule known as MEcPP, also seen in bacteria and malaria parasites.

The team observed that when there is an accumulation of MEcPP in plants, it triggers a reaction response, including salicylic acid. This insight could aid in modifying plants to become more resistant to the numerous environmental hazards it faces, especially in the onslaught of global warming due to climate change.

Jin-Zheng Wang, a co-author and plant geneticist from UCR, explains that at non-lethal levels, ROS are similar to an emergy call to action that enables the production of protective hormones in plants such as salicylic acid. However, ROS are double-edged swords, reports ScienceAlert.

He adds that the team would like to use the newfound knowledge to improve crop resistance which will be crucial in maintaining food supply amidst the increasingly hot, bright world.

Today, much remains unknown about the MEcPP molecule and its functions; however, understanding how the mechanism works could help experts harness it for producing plants that can better cope with various stresses and strains.

So far, we know that plants and animals are under increasing pressure from the warming world, and it remains unclear how many species will survive as average global temperatures continue to climb.

As the researchers pointed out, the stresses examined in the study - reaction to high heat, lack of water, and constant sunlight - are all currently being experienced by plants across the globe. If plants are in trouble, so are all other organisms in the food chain.