Azurin from Pseudomonas aeruginosa and its insecticidal activity against Spodoptera frugiperda (J.E. Smith)

Fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a major pest of maize, and its control requires the use of insecticides. The increasing prevalence of insecticide resistance in S. frugiperda highlights the urgent need for new, effective, and environmentally safe strategies. Azurin, a redox-active protein produced by Pseudomonas aeruginosa, was evaluated for its insecticidal potential against S. frugiperda larvae. Biochemical assays measured the effects on nutritional physiology and enzymatic activities in larvae. Larval bioassays revealed that azurin exhibited potent toxicity, with an LC₅₀ values of ۹۴.۴۰, ۴۲, ۱۳.۳۰, ۳.۵۵ µg/mL after ۲۴, ۴۸, ۷۲ and ۹۶ h, respectively of exposure. The larval mortality rate increased in a time- and dose-dependent manner. Azurin also negatively affected the development of insect along with significant decline in relative growth and consumption rate as well as efficiency of conversion of ingested and digested food of insect. The azurin significantly decreased the reproductive potential of insect. A significantly decrease in the activity of various digestive enzymes and detoxifying enzymes was also observed that might be associated with reduced survival of this insect. These results suggest that azurin exhibits significant larvicidal activity and the ability to disrupt S. frugiperda metabolism functions, making it a promising candidate for controlling this pest.

کلیدواژه ها:

Azurin ، Fall armyworm ، Pseudomonas aeruginosa ، Nutritional physiology ، Biochemical analysis