Sesquiterpene synthase producing mainly delta- and gamma-cadinene with traces of several other sesquiterpenoids, including alpha-copaene. Associated with the production of sesquiterpenes responsible for the aroma of the fruit. (2E,6E)-farnesyl diphosphate = (+)-gamma-cadinene + diphosphate (2E,6E)-farnesyl diphosphate = (1S,8aR)-delta-cadinene + diphosphate Binds 3 Mg(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. Expressed in the rind tissues of ripe fruits. Expressed during ripening. The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family. Tpsa subfamily.