本文研究外源赤霉酸（gibberellic acid，GA3）处理对采后番茄果实抗冷性的影响。以绿熟期的浙粉702番茄果实为试材，室温下经0、0.2、0.5和1 mM GA3水溶液处理30 min后，在4 ℃条件下贮藏，分别在贮藏第0、3、7、14、21和28 d时取样，于室温下放置3 d后测定番茄果实的冷害指数以确定适宜的GA3浓度，并观察此浓度GA3处理后番茄果实微观结构变化，测定其丙二醛（malondialdehyde，MDA）含量、离子渗透率以及细胞膜磷脂相关酶：磷脂酶C（phospholipase C，PLC）、磷脂酶D（phospholipase D, PLD）、脂氧合酶（lipoxidase，LOX）和细胞壁降解酶多聚半乳糖醛酸酶（polygalacturonase，PG）活性的变化。结果表明：与对照组相比，外源0.5 mM GA3处理能有效减轻番茄果实的冷害症状、保护细胞的微观结构、抑制MDA含量和离子渗透率的增加以及PLC、PLD、LOX和PG活性的增强，从而提高采后番茄果实的抗冷性。

The effect of exogenous gibberellic acid (GA3) treatment on chilling stress tolerance of harvested tomato fruits was investigated in this study. Solanum lycopersicum L. ‘Zhefen’ No. 702 at the mature green stage was used as the test material, treated with 0, 0.2, 0.5, or 1 mM GA3 aqueous solution at room temperature, and stored at 4 ℃. Tomato samples were collected on days 0, 3, 7, 14, 21, and 28, and stored at room temperature for three days before the chilling injury index was measured to determine the most suitable GA3 concentration. In addition, microstructure changes, malondialdehyde (MDA) content, electrolyte leakage, and changes in the activities of phospholipase C (PLC), phospholipase D (PLD), lipoxidase (LOX), and polygalacturonase (PG) were measured. These results showed that compared with the control, 0.5 mM exogenous GA3 treatment effectively alleviated the chilling injury symptoms, protected cellular microstructure, and significantly inhibited increases in the MDA content, electrolyte leakage, and activities of PLC, PLD, LOX, and PG, thus enhancing the chilling stress tolerance of postharvest tomato fruits.

国家自然科学基金项目(31401551)；基本科研业务费专项（0032015017）；中国农业科学院科技创新工程