How can sunflowers tell the direction?

Sunflowers can tell their direction by the content of auxin. Because under the irradiation of sunlight, the auxin content of sunflower will increase on its backlight surface, thus stimulating the cells on the backlight surface to elongate and rotate towards the sun. After the sun goes down, the sunflower auxin will be redistributed, making the sunflower turn to the east again.

After the sunflower disc is in full bloom, it will not turn to the sun, but will be fixed in the east. Sunflower pollen will be burned by high temperature, and then it will always be fixed in the east to avoid direct sunlight at noon and reduce radiation.

Extended data

The role of sunflower auxin: backlight function, when sunflower is irradiated by light energy, it grows and runs to the backlight side to adjust the orientation of sunflower; It can promote (inhibit) the growth of cells and accelerate (slow down) the division and reproduction of cells. Polar transportation, from the upper end to the lower end of the form, is irreversible.

Sunflowers are suitable for growing environment: suitable for living in sunny, humid or disturbed areas.

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