An N-acetyl Glucosamine Specific Latex Lectin Induced Larvicidal Defense Against Melon Fly Infestation in Selected Cucurbitaceous Fruits

Many plant lectins expressed in fruits are known to possess defensive mechanisms and larvicidal functions. Present studies aimed to compare the lectin protein expression in selected cucurbit fruits to understand the resistance and susceptibility against melon fly infestation. Both susceptible (bitter gourd, snake gourd and cucumber) and resistant (chayote and bottle gourd) fruit latex sap were prepared and lectin proteins were characterised by hemo and leuco agglutination activity. Some are partially purified to identify glycocode as N-acetyl glucosamine and stability was assessed for proteases, pH and temperature. The larval growth was inhibited and was fed at low concentrations and was found dead at high concentrations after incubation for about 24 h. The histopathology indicates the lectin-induced damage to the larval gut region, indicating lectin-induced toxicity. The lectin protein induces toxicity by binding and inducing digestive impairment in larvae growth and causing mortality. The comparative observations indicate that lectin protein expressed from the fruit tissues of chayote and bottle gourd secretes latex and defends against the melon fly larval infestation and provides resistance. The study explores the importance of N-acetyl glucosamine-specific lectin as a defensive protein in resistant cucurbits fruits against melon fly infestation.