The discovery of the hormone family could be the key to improving crop yields

Crops are often exposed to harsh growing conditions
.
Factors such as disease, extreme temperatures, and saline lands force plants to use energy to cope with the resulting stress, rather than using it for growth
.
This is known as the "growth-stress response trade-off.
"
Now, a team of researchers from Nagoya University has discovered a previously unknown pathway that can regulate whether plants use their resources to grow or use their ability to
withstand pressure.
This discovery could lead to the control of stress responses under agricultural conditions and increase crop yields
.
They published the findings in the journal Science.

A research team led by Professor Yoshikatsu Matsubayashi and Assistant Professor Mari Ohnishi of the Graduate School of Science at Nagoya University in Japan investigated the role of
hormones and their receptors in plant stress responses.
They focused on three receptors whose counterparts have not yet been identified
.
Using thale cress, a small flowering plant, they discovered the PSY family, which acts as a hormone that binds to these receptors and regulates the switch
between stress response and growth.

When the researchers investigated the pathway, they made an unexpected discovery
.
In general, receptors and hormones act like locks and keys, while hormones (in this case, a peptide PSY hormone) act like keys necessary to turn on a biological process
.
However, in this study, those plant cells that did not produce PSY had a positive stress response
.
Thus, this suggests that the PY "key" present in the receptor "lock" does not activate the stress response, but keeps it off
.

To test the nature of the stress response, the researchers grew plants under extreme stress conditions such as high temperatures and salt, and infected them with bacteria
.
Plants that lack PSY receptors or are continuously fed the PSY hormone are unable to respond adequately to stress, resulting in reduced
survival rates.
The scientists concluded that stressed plants stopped releasing PSY, and the loss of PSY triggered stress response genes
.

To explain this phenomenon, the researchers proposed a mechanism by which damaged cells reduce the concentration
of the PSY hormone in the cell layer near the damaged site.
This lack of PSY triggers a stress response
.
Importantly, this may explain why even damaged plants can send information
.
Damaged plant cells may stop the release of the PSY hormone, which activates the stress response, rather than using their limited resources to create new signals
.
This mechanism will balance stress resistance and associated energy costs
.
Therefore, even in the most stressful environmental conditions, plants can still grow
by managing their limited resources.

"Most of the mechanisms found in Arabidopsis thaliana can also be found
in other plants.
Therefore, our findings apply to all crops
.
"This mechanism makes it possible to artificially control the balance between stress resistance and yield, which is a trade-off relationship
.
" In recent years, more and more crops have been planted in
plant factories.
When crops are grown indoors, this is a low-stress environment, and the pressure response systems required to withstand fluctuating natural outdoor environments are not always necessary
.
Cultivars with low PSY receptor activity in plant factories may yield higher yields
in these controlled environments.
”