New Study Explains How And Why Sunflowers Follow Sun Movement [VIDEO]

A new study tried to solve the mystery behind how young sunflowers follows the path of the sun across the sky. The beautiful yellow flowers turn east in the morning to face the rising sun and then moves across the sky during the day before heading westward by dusk. At night, when the sun disappears, the flowers turn their face back east in order to catch the first rays of sunlight at dawn.

According to the study conducted by a team of biologists from the University of California, the sunflower's ability to detect light and its internal clock together acts on growth hormones, to follow the movement of the sun. It was found that the east sides of the flowers' stems grew more rapidly than the west sides during the day time. However, at night, the west side stems grew faster turning the flower head back east, reported New Scientist.

For the study, funded by the National Science Foundation's Plant Genome Research Program, biologist Stacey Harmer and her team placed sunflowers in a room which had adjacent lights that mimicked the movement of the sun and were turned on and off sequentially. The research team created an artificial 30-hour day-night cycle using the lights.

It was found that the sunflowers were a bit confused when exposed to a 30-hour day cycle and didn't move back and forth on a regular schedule. However, when the lights were reset to a 24-hour cycle, the plants began bending from east to west as normal. The findings suggested that an internal 24-hour circadian rhythm is responsible for the movement of the sunflowers, reported Tech Times.

In another experiment, the researchers prevented outdoor potted sunflowers from tracking the sun. It was found that the plants grew smaller than those that followed the sun. Furthermore, in order to understand why mature sunflowers end up facing east when they are done growing, the research team grew sunflowers in pots and rotated them to the west. Using an infrared camera, the researchers found that the sunflowers which faced east heated up more quickly in the morning and also attracted five times as many pollinating insects. The study findings have been published in the journal Science.