关键词: 香蕉, 乙烯, 钙, 乙烯形成酶(EFE), 1-氨基环丙烷-1-羧酸(ACC), 1-(丙二酰氨基)环丙烷-1-羧酸(MACC)

Abstract: Banana (Musa acuminata cv. ‘Dwarf Davendish’) fruit tissues were vacuum infiltrated with CaCl₂ solutions in order to determine the influence of calcium upon ethylene production, EFE activity, ACC content and ACC/MACC ratio. The results showed that calcium treatment inhibited ethylene production in both peel and pulp, particularly in peel. Ethylene production in peel treated with 3 concentrations of CaCl₂ solutions (0.2, 0.6 and 0.8 mol/L) remained lower than that in the control throughout the period of 2-6 hours after treatment.Ethylene production in pulp infiltrated with 0.2 and 0.6 mol/L CaCl₂ were inhibited during 2-3 hours after treatment,and ethylene production was reduced by 0.8 mol/L CaCl₂ treatment throughout 2-6 hours (Fig. 1). Calcium infiltration (with 0,2, 0.4 and 1.0 mol/L CaCl₂) lowered the internal ACC level in both peel and pulp (Tab. 1).EFE activity in peel and pulp treated with 0.05, 0.1, 0.2 and 0.5 mol/L CaCl₂ were reduced (Tab. 2). The result also showed that calcium treatment contributed to the change of ACC/MACC ratio (Fig. 2). The results suggest that the inhibition of Ca²⁺ on ethylene production in banana tissues, does not merely act on the step of ACC to ethylene, Ca²⁺ may also regulate both ACC biosyn thesis and the bioconversion of ACC to MACC.

Key words: Banana, calcium, ethylene (C₂H₄), ethylene forming enzyme (EFE), 1-aminocyclopropane-Icarboxylic acid (ACC), 1-malonyl-aminocyclopropane-1-carboxylic acid (MACC)