Abstract
The petiole curvature plays a major role in light interception, but the mechanisms are not clear. We examined the petiole curvature in Chenopodium album L. grown under two different light conditions (360, 50 μmol m-2 s-1).
To specify the light perception site for induction of the curvature, the lamina or petiole were separately illuminated with white light continuously. The curvature was induced most effectively when the abaxial side of petiole was illuminated. The amount of curvature depended on the growth light condition. Under continuous illumination of the abaxial side, the petiole kept on curving. In natural condition, however, the curvature may cease when the lamina receives optimal light intensity. We investigated the light perception site for cessation of the curvature. The adaxial side of petiole was the most sensitive site. Furthermore, blue light was effective to induce the curvature, and blue and red light were effective to stop the curvature.
