Isolation of the Astacin-like metalloprotease coding gene (astl) and assessment of its insecticidal activity towards Spodoptera littoralis and Sitophilus oryzae

[摘要] Astacin-like metalloprotease,possessing a zinc (II) ion in the catalytic center is one of the toxic proteases. It exists in a variety of organisms, including fish, frogs, birds and insects. The present investigation was conducted with the main goal of assessing the efficacy of astacin like metalloprotease toxin for pest control and to determine the probability of using it to produce a new biopesticide that is friendly to the environment. Therefore, the full length of astl cDNA was cloned from spider species, Hasarius adansoni. Sequencing of the cloned astl cDNA has proved that its full length includes 802 bp with 714bp open reading frame encoding 238 amino acids. 486bp of the catalytic domain was cloned and expressed by the yeast expression system Pichia pastoris, and its insecticidal activity was determined towards two species of agricultural insects from two different orders, Spodoptera littoralis (Lepidoptera:Noctuidae) and Sitophilus oryzae (Coleoptera:Curculionidae). Bioassay was performed using three concentrations (100,500 and 1000 μg/ml) for four days for S. littoralis and 14 days for S. oryzae. At the concentration 1000 μg/ml, the mortality ratio was 69.3%±2.51, 65%±2.6 and 64.0%±3.0 for first instar S. littoralis, second instar S. littoralis and S. oryzae adults respectively. Finally, the present study represents an evidence that the use of zinc metalloproteases derived from different spiders may play an effective role in insect control.

[学科分类] 生物科学（综合）

[关键词] Metalloprotease;Spodoptera littoralis;Sitophilus oryzae