EFFECT OF TROPOLONE AND HINOKITIOL ON IN-VITRO ACTIVITIES OF 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE AND OXIDASE IN WOUNDED WINTER SQUASH MESOCARPS

Effects of tropolone and hinokitiol on ethylene production, ACC conten t and in vitro activities of ACC synthase and oxidase were investigate d by using wounded mesocarp tissues of winter squash fruit (Cucurbita maxima Duch. cv. Ebisu). Tropolone over the range from 1 to 500 ppm in hibited ethylene production by 33 to 98% and reduced ACC content by 48 to 83%, whereas hinokitiol treatment reduced them by 17 to 97% and by 34 to 83%, respectively. Both tropolone and hinokitiol were found to inhibit ethylene production through suppression of activities of the t wo key enzymes.