The Effect of Epidermal Wounds on the Uptake and Transport of Solutions Fed to Stems and Petioles of Plants

Incisions used to offer radioisotopes and conditioning chemicals were monitored for their effect on the transport system, using movement of 11C-photosynthate and 14C-sucrose to study phloem transport in Helianthus and India ink to study xylem water movement in Heracleum. It was found that cuts made in air were more effective than cuts made under water, in part because both radioisotopes and conditioning chemicals penetrated more readily when cuts were made in air. Incisions made while the stem was under a backpressure, created by a pressure bomb, neutralized the release of pressure by the cut as seen in the movement of India ink in the xylem and biopotential changes as seen in vascular bundles.