Small brains help seeds decide when to germinate

Plant seeds can use miniature "brains" to decide whether to sprout now or wait for more, says a new study from the University of Birmingham in England. Although these brains are not like traditional gray matter, they use the same architecture to process information based on hormone signals.

Thinking bamboo

One of the co-authors of the study, George Bassel, says that people make decisions using small groups of special cells in certain areas of the brain. Seeds use the same mechanism as the cells of the nervous system. Scientists were led to this conclusion by the fact that the seeds germinate under the most favorable conditions for them. To understand what they base this decision on, the researchers created a digital atlas of all the cells inside the seeds of the Tal Rezhovidka plant.

As a result, it turned out that two hormones that play a role in germination - gibberellin (GA) and abscisic acid (ABA) - are produced at the tip of the seed root. The hormone GA is responsible for the “do not grow” command, and the hormone ABA is responsible for the “forward” command. Between the two sections of cells producing these hormones, signals constantly passed along the principle of tug of war. At first, the GA hormone was stronger, and the seeds patiently waited for more favorable conditions. As the conditions improved, the signals from the ABA section became stronger, and as a result, a critical moment came, after which the seeds sprouted.

Roots of the mind

According to a similar principle, the human brain operates. In the motor zone of the human cerebral cortex, two separate regions initiate a “go” or “no” signal, either facilitating or obstructing the decision to move. A similar mechanism exists in animals.

The most interesting thing about this is that these mechanisms in animals and plants appeared independently of each other: their last common ancestor was a unicellular alga-like organism that lived 1.6 billion years ago, and they clearly could not adopt such complex nervous activity from it.

Scientists have previously confirmed the idea of "thinking" of plants. Studies have shown that seedlings are drawn to the sounds of certain frequencies or accelerate their growth if there are competitive species nearby. And the results of the 2007 experiments say that plants can communicate with each other when danger is nearby.

In the course of experiments with seeds, the team was able to change the activity of hormones and showed that by manipulating the level and frequency of transmission of hormonal signals, germination can be controlled. This opens up enormous opportunities in breeding plant varieties that are more resistant to external manifestations.