Effect of tropolone and hinokitiol on in vitro activities of 1-aminocyclopropane-1-carboxylate synthase and oxidase in wounded winter squash mesocarps

Abstract

Effects of tropolone and hinokitiol on ethylene production, ACC content and in vitro activities of ACC synthase and oxidase were investigated by using wounded mesocarp tissues of winter squash fruit (Cucurbita maxima Duch. cv. Ebisu). Tropolone over the range from 1 to 500 ppm inhibited 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 two key enzymes.