How And Why Sunflowers Point To The Sun

A recent piece of research revealed how and why sunflowers point to the sun. As sunflowers follow the light of the sun, they turn towards that source of light and warmth. These plants turn from east to west during the day, and then reverse their spin, swinging from west to east to be able to catch the first sunrays in the morning, at daybreak.

But how do otherwise still plants do this?

The research published in the Science journal came up with an answer: apparently, sunflowers resemble animals in one aspect: they have a circadian rhythm. This otherwise animal trait is similar to an internal clock that depends on the outside world.

In the daytime, the sunflower’s circadian rhythm system tells the plants’ stem cells on the western side to grow longer, which makes the sunflower to lean towards the west. During night time , the message reverses so the plants bounce back eastwards.

This is a premiere example of a plant’s internal clock-influencing growth in natural environments, pointed out professor Stacey Harmer form the University of California.

Although they don’t actually sleep, a lot of plants have “gene clocks” similar to those in animals, which tell them when to go to sleep and when to wake up. Now, the connection between these genes and the release of the hormone called auxin which makes stem cells grow has been made.

And sunflowers helped accomplish those results.

As sunflowers grow, they stop moving around as much as young sunflowers do. These new conclusions suggest that plants are a lot more animal-like than people believe.

The peculiar behavior of sunflowers was first observed in 1898, but the new study is the first one that explains how the mechanism works. The sunflower’s rotation leads to overall healthier, taller sunflowers.

And as bees like warm flowers to pollinate, they always choose the sunflower over a flower less exposed to the sun.

Another strange conclusion of the study is that sunflowers perceive several types of light: UV, green, red, blue, and far red. Some of these wavelengths, like UV and far-red, cannot be detected by humans.

This research has applications in the field of stem cell research and innovative treatments based on growth hormones.

Image Source – Wikipedia