Plants have feelings too. Although they are not conscious, plants release hormones in response to stimuli such as mechanical stimuli – like touch, wind, or rain – light, water, gravity, and nutrients. For example, when you run a knife down a rhubarb stalk, thousands of genes are activated, and a stress response is triggered.
While this phenomenon has been known since the days of Darwin, however, scientists have not been able to completely piece together the whole story of mechanical stimuli. A research team from Lund University in Sweden has recently published a paper explaining the core genetic keys to this process, shooting forward understanding of the subject.
How do plants get stressed?
“We exposed the plant thale cress to soft brushing, after which thousands of genes were activated and stress hormones were released. We then used genetic screening to find the genes that were responsible for this process”, explains Olivier Van Aken, a researcher who worked on the study.
They found that external influences had a huge impact on the plant’s defense mechanisms. The hormone jasmonic acid is well known to be at the core of this process, controlling a complex network of touch-sensitive responses. Through the team’s extensive work, they were able to uncover three new molecules that play key roles in this pathway.
“Our results solve a scientific mystery that has eluded the world’s molecular biologists for 30 years. We have identified a completely new signaling pathway that controls a plant’s response to physical contact and touch. Now the search for more paths continues”, says Essam Darwish, who also worked on the study.
How will this knowledge improve crop yield?
With a growing world population and climate change influencing crop yield, understanding how we can best work with plants is huge to humans’ advantage. The group believes understanding the influence of mechanical stimuli could lead to changes in modern agriculture at its core. “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”, concludes Olivier Van Aken.
The team is further investigating how mechanical touch can boost crop yield and looking at global practices that do so. One of these is a centuries-old Japanese tradition that tramples grain during its growth phase. It is thought that this improves the plant’s stress resistance and in turn, improves yield.
Source study: Science Advances – Touch signaling and thigmomorphogenesis are regulated by complementary CAMTA3- and JA-dependent pathways
