A University of Missouri-led research team recently found a new method for assessing stress in plants: measuring levels of reactive oxygen species (ROS), a once-malicious set of molecules produced by anything that uses oxygen (including animals, plants, and humans), and has now found that they play an important role as a communication signal indicating when plants are under stress. Given that plants are currently experiencing multiple stresses such as droughts, heatwaves or floods, these results could open up new ways to increase plant resilience to environmental stresses to avoid yield losses.
“Reactive oxygen species (ROS) are key signaling molecules that allow cells to quickly respond to various stimuli,” the study authors write. “In plants, ROS play a critical role in the recognition of abiotic and biotic stresses, the integration of various environmental cues, and the activation of stress response networks, thereby contributing to the establishment of plant defense mechanisms and resilience”
Although scientists have long known that plant stress is associated with yield loss, previous research has typically focused on how plants respond to just one stressor. However, plant survival often sharply decreases with an increase in the number of stress factors.
“When the stressors of heat and drought are added together, the plants have nowhere to draw groundwater from, so they close their stomata [поры листьев]leading to overheating of the leaves,” said study lead author Ron Mittler, a botanist at the University of Missouri.
That’s why the combination of drought and heat is really dangerous, because the temperature of the leaves is much higher than in heat-only plants. The change can be two to four degrees, and it can make the difference between life and death.”
Moreover, with a further increase in the number of stress factors, the chances of plants to survive decrease even more. According to Professor Mittler, the key to protecting plants from environmental stress is to keep ROS levels under control. While too much or too little ROS can be detrimental, optimal levels greatly protect plants by increasing their resistance to a wide variety of stressors. Further research is needed to determine optimal levels of ROS and develop reliable methods for their control to protect crops.
The study is published in the journal Nature Reviews Molecular Cell Biology.