ETHYLENE-ENHANCED SENESCENCE OF LEAFY VEGETABLES AND FRESH HERBS
One of the most common postharvest problems of green vegetables and fresh herbs is associated with their rapid senescence, a process which is thought to be regulated by ethylene, the senescing hormone. In the present work various senescence parameters as well as patterns of ethylene and CO2 evolution were screened simultaneously in detached leaves of spinach, parsley and watercress, in order to study their senescence process. Senescence was enhanced by wounding, by application of the ethylene precursor - ACC (0.1 mM), and by gasing the tissue with 10 μl/L ethylene. Retardation of senescence was achieved by application of inhibitors of ethylene biosynthesis (50 mM AOA) and action (60 μM Ag+, 11% CO2). All three plant systems, consisting of intact leaves, leaflets or leaf discs, exhibited two surges of ethylene production during their dark incubation. The first peak occurred in response to excision or detachment, while the second one coincided more or less with commencement of senescence. A positive correlation between the level of wound-ethylene production and the rate of senescence has been found. The findings suggest that ethylene plays a significant role in accelerating senescence processes of leafy vegetables and herbs.
Philosoph-Hadas, S., Pesis, E., Meir, S., Reuveni, A. and Aharoni, N. (1989). ETHYLENE-ENHANCED SENESCENCE OF LEAFY VEGETABLES AND FRESH HERBS. Acta Hortic. 258, 37-46