Department of Biochemistry, University of Agricultural and Horticultural Science, Shivamogga 577204, Karnataka, India.
Department of Studies and Research in Biochemistry, Jnana Shayadri, Kuvempu University, Shimoga 577203, Karnataka, India.
Molecules. 2021 Oct 20;26(21):6345. doi: 10.3390/molecules26216345.
Melon fly () is the most common pest of cucurbits, and it directly causes damage to cucurbit fruits in the early developmental stage. The infection of fruit tissues induces oxidative damage through increased generation of cellular reactive oxygen species. The effects of melon fly infestation on the production of defensive enzymes and antioxidant capabilities in five cucurbit species, namely, bottle gourd, chayote, cucumber, snake gourd, and bitter gourd, were investigated in this study. The total phenolic and flavonoid content was considerably higher in melon fly infestation tissues compared to healthy and apparently healthy tissues. The chayote and bottle gourd tissues expressed almost 1.5- to 2-fold higher phenolic and flavonoid contents compared to the tissues of bitter gourd, snake gourd, and cucumber upon infestation. Defensive enzymes, such as peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), and catalase (CAT), were high in healthy and infected tissues of chayote and bottle gourd compared to bitter gourd, snake gourd, and cucumber. The activity of POD (60-80%), SOD (30-35%), PPO (70-75%), and CAT (40-50%) were high in infected chayote and bottle gourd tissue, representing resistance against infestation, while bitter gourd, snake gourd, and cucumber exhibited comparatively lower activity suggesting susceptibility to melon fly infection. The antioxidant properties were also high in the resistant cucurbits compared to the susceptible cucurbits. The current research has enlightened the importance of redox-regulatory pathways involving ROS neutralization through infection-induced antioxidative enzymes in host cucurbit resistance. The melon fly infestation depicts the possible induction of pathways that upregulate the production of defensive enzymes and antioxidants as a defensive strategy against melon fly infestation in resistant cucurbits.
瓜实蝇（Melon fly）是葫芦科作物最常见的害虫，它在早期发育阶段直接损害葫芦科果实。果实组织的感染通过增加细胞活性氧的产生而引起氧化损伤。本研究调查了瓜实蝇侵害对 5 种葫芦科物种（葫芦、佛手瓜、黄瓜、蛇瓜和苦瓜）果实组织中防御酶和抗氧化能力产生的影响。与健康和明显健康的组织相比，受瓜实蝇侵害的组织中的总酚和类黄酮含量明显更高。与苦瓜、蛇瓜和黄瓜的组织相比，受侵害的佛手瓜和葫芦组织表达的酚类和类黄酮含量几乎高出 1.5-2 倍。防御酶，如过氧化物酶（POD）、超氧化物歧化酶（SOD）、多酚氧化酶（PPO）和过氧化氢酶（CAT），在健康和受感染的佛手瓜和葫芦组织中均高于苦瓜、蛇瓜和黄瓜。POD（60-80%）、SOD（30-35%）、PPO（70-75%）和 CAT（40-50%）的活性在受感染的佛手瓜和葫芦组织中均较高，代表对侵害的抗性，而苦瓜、蛇瓜和黄瓜的活性较低，表明对瓜实蝇感染的敏感性。抗氧化特性在抗性葫芦科中也高于敏感葫芦科。目前的研究说明了涉及 ROS 中和的氧化还原调节途径的重要性，这些途径通过感染诱导的抗氧化酶在宿主葫芦科抗性中起作用。瓜实蝇的侵害描绘了可能诱导途径的情况，这些途径上调防御酶和抗氧化剂的产生，作为抗性葫芦科抵御瓜实蝇侵害的防御策略。
