Studies on the movement and distribution of ethylene in Vicia faba L

In Vicia faba ethylene does not appear to move between different parts of the plant in physiologically significant amounts. The 'resistance' to longitudinal movement is such that lateral emanation effectively isolates different parts of the plant from each other. When emanation is prevented, ethylene can be channelled to any part of the plant. Exposure of one section of a plant to (14)C-labelled ethylene (up to 200 μl/l) increased the internal concentration in other parts with ethylene that did not originate from the feeding chamber. A basipetal gradient of endogenous ethylene concentration was found in the lacuna of intact plants, the source of ethylene being the stem tissue. The permeability of stem tissue to ethylene decreases with age. The concentration of ethylene in tissues surrounding the lacuna is always higher than that in the lacuna and it is argued that 'compartmentation' of ethylene occurs within these tissues.