Question

Does auxin detect light?

Answer 1

Auxin:

1. Plants respond to light by showing growth movement towards the light. It is known as phototropism.
2. The growth movement is caused by the action of the auxin hormone, a phytohormone.
3. Auxin hormones detect light and by the synthesis of this hormone, plant movement occurs.
4. Auxin hormone works in the following ways:
   1. If a plant is kept open and receives light from above, then auxin diffuses uniformly down the stem. Due to the presence of auxin equally on both sides, the stem grows up straight because both sides of the stem show growth at the same time
   2. If a plant receives light from only one side, then auxin hormone moves from the tip and is concentrated on the side that has shade. Due to the presence of auxin in the shady region, there is unequal growth in the two sides resulting in growth of the stem towards the light.
5. After detecting light, auxin is broken down in light-exposed regions and diffuses to the region of shade. Unequal distribution of auxin causes phototropism.