HORTICULTURE

Detailed explanation-1: -In case of extreme or high light conditions the auxin of the plant gets destroyed which leads to the formation of the weak plant and in some cases it causes senescence of the plant.

Detailed explanation-2: -Light manipulates specific responses by controlling the sensitivity of the response to auxin at specific sites in the plant. Light regulates auxin levels to influence growth at the tissue level, whereas coordinated development among organs is achieved through light control of auxin distribution through the seedling.

Detailed explanation-3: -Under normal light conditions auxins are spread out in the plant. But when sunlight varies, auxin is broken down on the sunnier side of the stem. The higher concentration of auxin on the shady side causes the plant cells on that side to grow more so it bends toward the light.

Detailed explanation-4: -Phototropisms. In a stem, the shaded side contains more auxin and grows longer, which causes the stem to grow towards the light. The plant does NOT bend towards the light. It grows because the auxin causes the cells to elongate on the shaded side, so this side grows more.

Detailed explanation-5: -Scientists originally thought auxin was destroyed by light but it was disproved by the fact that plants growing in the dark and plants growing in unilateral light had similar auxin levels.