LEAF-DERIVED PROTEOLYTIC ENZYMES AS ECO-FRIENDLY BIOCONTROL AGENTS FOR INSECT PEST MANAGEMENT

The extensive use of synthetic insecticides has raised significant environmental and health concerns, necessitating the development of sustainable and eco-friendly pest management strategies. The present study investigates the isolation, characterization, and insecticidal potential of proteases derived from vegetable leaves against economically important insect pests, including Sitophilus oryzae. Plant-derived proteases are integral components of plant defense systems and can adversely affect insect growth and survival by disrupting digestive processes. Fresh vegetable leaves were subjected to protein extraction and purification using ammonium sulfate precipitation. The partially purified proteases were characterized with respect to molecular weight, which showed a protease range of ~40 kDa and ~55 kDa. The optimum pH was observed at pH 7; temperature stability was observed at 37℃. Insecticidal efficacy was evaluated through laboratory bioassays by incorporating protein extracts into artificial diets and conducting feeding assays. Dose-dependent activity was observed, which showed that as the dose was increased from 0.5 ml, 2 ml, and 5 ml, there was mortality of the pest compared with castor oil as the control. The isolated proteases exhibited significant proteolytic activity, as demonstrated by destaining results, and showed pronounced adverse effects on both target pests, resulting in reduced growth and increased mortality. These findings highlight the potential of vegetable leaf–derived proteases as natural bioactive agents for pest control. The study provides valuable insights into the utilization of plant-based insecticidal proteins for the development of environmentally safe biopesticides, thereby contributing to sustainable agricultural practices and reducing dependence on synthetic chemical insecticides.