What happens when coleoptiles are illuminated with directional light from the side instead of from directly overhead?

Question

Quizplus · Accepted Answer

When coleoptiles are illuminated with directional light from the side, auxin, a plant growth hormone, is transported away from the lighted side. This differential distribution of auxin causes the cells on the darker side to elongate more than those on the lighted side, leading to the bending of the coleoptile toward the light source.

What Happens When Coleoptiles Are Illuminated with Directional Light from the Side