The reason why sunflowers are facing the sun has been found

It took many centuries until now, scientists to really understand the exact cause of the phenomenon, sunflowers always face the sun. New Scientist led the study recently published in Science magazine.

When it comes to sunflowers, we all know that this is the kind of flower that always faces towards the sun. But the reason why flowers have such strange properties is not clear to everyone.

According to Wikipedia, the sunflower (also known as the zoological sunflower, the zodiac, the kneeling, the kneeling flower) is a flower of the Asteraceae family, scientific name is Helianthus annuus. The tree is native to Mexico and is a herbaceous plant that lasts for about a year, a large straight body with hard hair, often spotted, 1-3 meters high.

Sunflowers are flowers that always face towards the sun.

On the side of scientists, they also took centuries to find a satisfactory explanation for this natural question. However, just recently, a group of new scientists confirmed that the exact cause of the sunflower phenomenon was always pointing towards the sun.

Biological rhythm is the key factor?

Reality is completely different from what people imagine. Sunflowers are always directed towards the sun mainly due to the internal circadian rhythm . Daily movement not only improves leaf size but also makes sunflowers become more attractive to pollinators.

"This is the first example that a plant's biological clock can regulate growth in a natural environment," said lead researcher Stacey Harmer from the University of California. ".

Since 1898, scientists have begun to observe that the sunflower head moves from east to west, and continues a similar cycle the next day. However, at that time no one could discover that biological processes took place inside sunflowers.

Sunflowers are always directed towards the sun mainly due to the internal circadian rhythm.

In order to find the circadian rhythm under the influence of the sun in sunflowers, scientists have conducted a series of different experiments.

First, the team fixed the sunflowers so that they could not move the stalks. The purpose of the experiment is to verify whether sunflowers can break the law of daily movement.

Next, they brought sunflowers into the lab, using artificial light and continued to observe. The experimental group created a "fake" dawn cycle with artificial light. The light bulb is turned on by the solar movement cycle from east to west. Surprisingly, the movement mechanism of sunflowers remains unchanged as when exposed to the real sun. However, that cycle only exists perfectly within 24 hours. When the cycle lasts up to 30 hours continuously, sunflowers encounter a phenomenon of misidentification of the direction of movement.

Very quickly, scientists have questioned this phenomenon. Is there a regular circadian rhythm within 24 hours? So what really makes sunflowers move?

The movement of sunflowers is the result of one side of the tree growing faster than the other.

Gene contributes no less

Going deeper than the research team found that the movement of sunflowers is the result of one side of the tree growing faster than the other. And this growth depends on the time of day. This in turn leads to the phenomenon of sunflowers often leaning toward one side.

Scientists also found that a certain amount of genes seemed to be concentrated in the eastern direction of the tree in the morning, followed by a gradual flow of genes toward the trunk turning west in the evening. Harmer explained that such growth forms are very different from normal growth models of plants. It is worth noting that this cycle occurs daily, steadily over a 24-hour rotation.

More importantly, the movement of sunflowers brings great benefits. The team found that the experimental flowers that were not turned towards the Sun usually had 10% smaller leaves than the average. For plants placed west in the morning, they attract up to five times more bees and insects than the opposite plants.

The temperature chart of sunflowers changes throughout the day, red represents high temperatures.

For those who have experienced long-time sunflower cultivation, they must have known this cycle. However, this is the first time scientists can successfully explain the phenomenon of sunflower motion based on science, and find out the relationship between gene expression and the change of reality. object.

According to scientist C. Robertson McClung, of Dartmouth College in New Hampshire, the United States claims that a study to demonstrate circadian rhythms can help plant growth be one of the hardest areas of scientific research. great. For him, this is one of the best proofs to date, to answer the phenomenon that has been a headache for so many scientists in the world.

It is known that the study was published in the journal Science recently.