苯并噻重氮和茉莉酸甲酯对采后香蕉果实抗病性及相关酶活性的影响

【目的】探讨BTH(苯并噻重氮)和MeJA(茉莉酸甲酯)对采后香蕉果实抗病性诱导的效果及其对几种抗病相关酶活性的影响。【方法】分别用BTH和MeJA溶液对香蕉果实作喷雾处理后，将香蕉贮藏于22℃，观测发病情况和防御酶活性的变化。【结果】与未处理果实相比，经BTH和MeJA处理后的香蕉果实自然发病的病情指数显著降低。另外，处理后的果实接种炭疽菌后，病斑直径和发病率也显著降低。对过氧化物酶（POD）、过氧化氢酶（CAT）、多酚氧化酶（PPO）、苯丙氨酸解氨酶（PAL）、β-1,3-葡聚糖酶和几丁质酶等抗病相关酶活性的测定表明，无论对于接种还是未接种炭疽菌的香蕉，BTH和MeJA处理均提高了该6种酶的活性。【结论】BTH和MeJA处理提高香蕉果实的抗病性可能是通过激活香蕉的防御系统而发挥作用。BTH和MeJA诱导的两种不同的抗病反应既存在差异又相互联系。

Induction of Disease Resistance by Benzothiadiazole and Methyl Jasmonate in Relation to Activities of Defense-Related Enzymes

【Objective】The effects of benzothiadiazole (BTH) and methyl jasmonate (MeJA) on induction of disease resistance in harvested bananas in relation to activities of several defense-related enzymes were investigated. 【Method】Harvested banana fruits were sprayed with BTH or MeJA solution before being stored at 22℃. The disease incidence and 6 defense-related enzymes were monitored during the storage. 【Result】Compared with the non-treated fruits, BTH and MeJA treatments significantly reduced the disease indices of non-inoculated bananas and the lesion diameter and disease incidence of bananas inoculated with Colletotrichum musae. The determinations of activities of the defense-related enzymes peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), β-1,3-glucanase and chitinase showed that BTH and MeJA treatments enhanced the activities of these six enzymes in both un-inoculated and inoculated banana fruits. 【Conclusion】The results suggested that the control of decay of postharvest bananas by BTH and MeJA may involve the activation of the disease-related defense system and that the defense response induced by BTH in postharvest banana fruits appeared to be different from and also related to that by MeJA.