New Delhi: Touch can trigger stress reactions in plants. However, the mechanism was not clearly understood and the molecular models explaining how plants react to stress have been very simple so far. Researchers at Lund University in Sweden have now solved this 30-year-old genetic mystery.
The study, describing the findings, was recently published in the journal Science Advances.
The scientists have found genetic keys which explain how plants respond so strongly to mechanical stimuli, and cracking this code could help lead to higher yields and improved stress resistance in crops in the future.
When one waters garden plants, they react directly at a biochemical level. When a rhubarb stalk is cut by a knife, thousands of genes are activated, and stress hormones are released.
How Do Plants React To Mechanical Stimuli?
Plants, unlike humans, cannot feel pain. However, they still react strongly to mechanical stimuli from human touch, hungry animals, wind and rain. Due to these external factors, the plant's molecular defence system is activated quickly. This, in turn, can contribute to plants becoming more resistant and flowering later.
Despite the fact that the phenomenon has been known since Darwin, there are still many question marks. The new study has examined the complex regulating networks that affect how the plant's defences are strengthened by external influences.
Findings Of The Study
In a statement released by Lund University, Olivier Van Aken, one of the authors on the papers said the researchers exposed the plant thale cress to soft brushing, after which thousands of genes were activated and stress hormones were released. Then, they used genetic screening to find the genes that were responsible for this process.
According to previous studies, the plant hormone jasmonic acid is an important mediator in touch signalling, and has been known to be a part of the plant's complex network of touch-sensitive responses. There are several unidentified pathways for jasmonic acid which have not yet been unveiled.
The researchers conducted extensive laboratory work, and identified three new proteins that play an important role in the plants' response to touch, the study said.
In the same statement, Essam Darwish, another author on the paper, said the results solve a scientific mystery that has eluded the world's molecular biologists for 30 years, and that the researchers have identified a completely new signalling pathway that controls a plant's response to physical contact and touch. Now, the search for more paths continues, Darwish added.
How The Study Is Important
Olivier Van Aken, one of the researchers of the new research, is also studying a centuries-old Japanese agricultural technology that involves trampling grain during the growth phase, to obtain more abundant harvests. According to the researchers, there is a lot of hidden knowledge about how mechanical stimuli can lead to higher yields and improved stress resistance in crops. In the long run, this knowledge can change modern agriculture at its core.
Oliver Van Aken said that given the extreme weather conditions and pathogen infections that climate change leads to, it is of utmost importance to find new ecologically responsible ways to improve crop productivity and resistance.