Inhibitory effect of proteinaceous extracts of wheat seeds against gut α-amylase activity of Helicoverpa armigera (Hübner) (Lep.: Noctuidea)

Abstract

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest that has evolved resistance mechanisms against insecticides. Inhibitors to insect α-amylase have already been demonstrated to be an important biological system in the control of insect pests. Thus, the aim of the current study was to study the effect of three wheat varieties (Aflak, Sivand and MV17) extracts against H. armigera larvae. Sodium chloride (0.1 M) was used to extract protein of wheat varieties. Results showed that different proteinaceous extracts have different effects on the insect α-amylase activity. At a low dose of Aflak, Sivand (1.063 μg ml−1 protein) and MV17 (1.156 μg ml−1 protein), only 34.79, 28.75 and 35.83% of the amylase activity was inhibited, respectively. Whilst at the highest dose of Aflak, Sivand (17 μg ml−1 protein) and MV17 (18.5 μg ml−1 protein) they caused 51.08, 46.27 and 54.86% inhibition of amylase activity, respectively. In gel electrophoresis, control enzyme showed three bands whilst treated enzyme with different concentrations of seed extracts different percentage of enzyme inhibition was observed. Obtained results showed that seed proteinaceous extract have potential to be used in order to combat pest damage.