A 30-year-old genetic mystery has been solved. It has previously been
established that touch can trigger stress reactions in plants. However,
the molecular models for explaining this process have been quite spartan
so far. Now researchers at Lund University in Sweden have found genetic
keys that explain how plants respond so strongly to mechanical stimuli.
Cracking this code could help lead to higher yields and improved stress
resistance in crops in the future.
When you water your garden plants,
they react directly at a biochemical level. When a knife edge cuts a
rhubarb stalk, thousands of genes are activated, and stress hormones are
Unlike humans, plants can not feel pain, but they still react strongly to mechanical stimuli from
human touch, hungry animals, wind and rain, for example. These external
factors lead to the plant's molecular defense system being activated
quickly, which in turn can contribute to plants becoming more resistant
and flowering later.
Although the phenomenon has been known since Darwin, there are still many question marks. A new study published in Science Advances has examined the complex regulating networks that affect how the plant's defenses are strengthened by external influences.
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, biology researcher at Lund
studies have shown that the plant hormone jasmonic acid is an important
mediator in touch signaling. It has also been known that jasmonic acid is
only part of the plant's complex network of touch-sensitive responses,
and that there are several unidentified pathways that have not yet been
unveiled. After extensive laboratory work, the researchers were able to
identify three new proteins that play a key role in the plants' response to touch.
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, biology researcher at Lund University.
What possible applications will
the new results have? Olivier Van Aken is also studying a centuries-old
Japanese agricultural technology that involves trampling grain during
the growth phase, to obtain more abundant harvests. The researchers
believe that there is a lot of hidden knowledge about how mechanical
stimuli can lead to higher yields and improved stress resistance in
crops. Knowledge that in the long run can change modern agriculture at
"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
More information: Essam Darwish et al, Touch signaling and thigmomorphogenesis are regulated by complementary CAMTA3- and JA-dependent pathways, Science Advances (2022). DOI: 10.1126/sciadv.abm2091