In the past, people have always believed that the flower plate of sunflower always faces the sun. It is the auxin of plants that plays a role. It is the auxin that distributes in the back part of the disk and stem to promote the cell division and growth there. However, the growth on the sunny side is correspondingly slow. Therefore, the plant bends and the sunflower disc rotates towards the sun.
Why is sunflower always facing the sun? What is the reason why sunflower flowers always turn to the sun?
However, in recent years, plant physiologists have found that the auxin content in the sunflower disc base is basically equal to that in the sunflower disk. Obviously, sunflower sunflower is not in the role of auxin. So, what's the reason for sunflowers to be sunny?
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Why is sunflower always facing the sun? What is the reason why sunflower flowers always turn to the sun?
Some people have done experiments in greenhouse, using cold light (that is, fluorescent lamp) instead of sunlight to simulate the direction of sunlight on the sunflower plate. Although it was taken from the East in the morning and from the West in the evening, the sunflower never turned. However, if the sun is replaced by a brazier and the light of the fire is blocked, the flower plate will turn towards the fire pot one by one, regardless of day and night, or East, West, north or south.
It can be seen that the rotation of the sunflower disc is not due to the direct influence of light, but because the sun heats the tubular florets in the sunflower disc, and the fiber at the base will shrink. This contraction enables the disc to actively change direction to accept the sunlight. Therefore, sunflower can also be called 'hot sunflower'.
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