Scientists from the Julius Maximilians University in Würzburg, Germany, have discovered a process by which plants generate a memory of droughts, activating a molecule that determines a smaller opening of their pores when they notice that the climate is drier. Thanks to this, they manage to lose less water and better cope with periods of greater dryness.
According to a press release , plants use a signaling molecule called GABA to remember the degree of drought. When dryness increases dangerously, the accumulation of this molecule in plant tissue becomes more intense during the day. The next morning, the amount of GABA determines whether the plant will open more or less the pores of the leaves. The width of the opening of these pores can limit the loss of water and generate its savings.
Known in the human being as the neurotransmitter of calm and relaxation, since it is capable of reducing stress and anxiety, GABA participates in multiple mechanisms of different living beings. In the case of plants, the GABA molecule appears to play a vital role in water-saving processes, according to the findings of German scientists.
GABA is known to be a signaling molecule that functions as a messenger substance of the nervous system in humans and animals. However, although plants do not have nerve cells or a brain, it has now been shown that GABA also participates in plant organisms in relation to memory-like processes.
THE CHARACTERISTICS OF THE PROCESS
According to Rainer Hedrich, one of the authors of the study published in the journal Nature Communications, “after studying how plants regulate their water balance for more than 35 years, finding a completely new and unexpected way of saving water in vegetables has been surprising and opens new avenues of research, “he said.
The specialists explained more details of the mechanism that allows saving a transcendental resource for plants. In principle, while a drought occurs, the production of the GABA molecule is triggered and inhibits the opening of the pores of the leaves. When conditions change, the GAD2 enzyme, responsible for converting glutamate to GABA, is genetically switched off. This allows the pores to remain open and the plant can lose more water.
However, when dryness increases again, the cells of the plant sphincter perceive stress autonomously, reacting to it with the production of GABA. In this way, and from the “memory” of previous droughts caused by stress, the genetic process previously indicated is reversed and the pores are closed, facilitating greater water savings.
A PLANT MEMORY
But this fascinating discovery around a kind of plant memory is not an isolated event. According to the scientists, the carnivorous plant Venus flytrap has something similar to a short-term memory, which allows it to count the number of times its prey touches it.
And the most surprising thing is that this process depends on the calcium level in the cells, the same pattern that regulates the enzymatic mechanisms related to the GABA molecule in plants.
There is no doubt that knowledge about water saving strategies and plant drought tolerance are increasingly important in times of climate change. In their study, the specialists were able to verify the process discovered in crops such as barley, beans and soybeans, in addition to verifying it in laboratory plants.