In a positive phototropic response of a coleoptile, the region of greatest curvature is brought about by the
- movement of auxins away from the region of curvature
- even distribution of auxins in all parts of the coleoptile
- inhibition of growth by auxins in the region f smaller curvature
-
concentration of auxins in the region of curvature
- absence of auxins in the coleoptile