The effect of chilling on ethylene production, membrane permeability and water loss of leaves of Phaseolus vulgaris.

When seedlings of Phaseolus vulgaris L. vv. Canadian Wonder are chilled at 5°C (45% relative humidity) (RH), the primary leaves lose fresh weitht, produce ethylene at an increased rate when transferred to 25°C and leak electrolytes at an increased rate when placed in water.Similar changes result from chilling excised leaves at 5°C 20% RH. However, chilling only leads to increased rates of electrolyte leakage in partially dehydrated leaves. Chilling alone or water deficits alone (up to 30% fresh weight loss) do not lead to increased leakage.In contrast fresh weight loss alone does lead to an increased rate of ethylene production. Although a similar potential for increased ethylene production at 25°C initially results from partial dehydration in both chilled and non-chilled leaves, this potential is maintained for longer at 5°C than at 25°C.