Characterization of α-amylase and its activity from mustard aphid Lipaphis erysimi (Kalt.) (Hemiptera) and its inhibition by Rorippa indica defensin |
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| Authors: | Poulami Sarkar |
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| Institution: | 1. Division of Plant Biology, Bose Institute, Kolkata, India;2. Present address: Department of Entomology, Volcani Centre, Rishon LeZion, Israel |
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| Abstract: | AbstractLipaphis erysimi Kaltenbach is one of the economically important pests of Indian mustard Brassica juncea. Plant defense against these pests include impairing digestive processes in the insect gut. Thus, for an effective pest management, it is imperative to understand the digestive enzymes present in the pest. The present study involves the characterization of mustard aphid α-amylase and the efficacy of a potent insecticidal agent, RiD (Rorippa indica defensin) against it. The total protein of L. erysimi was analysed to determine the α-amylase activity present in it. The relative α-amylase activity in the total protein was assayed by the dinitrosalicylic acid (DNS) procedure, using 1% soluble starch as substrate and was observed to be 2.32?±?0.025?U/mL of the total protein. The optimum temperature for α-amylase activity was found to be 35?°C and optimum pH was recorded as 6.5. Presence of RiD showed a decrease in the α-amylase activity in a non-competitive way. Moreover, cryo-sections of the aphid midgut also revealed bound RiD in the confocal analysis. |
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| Keywords: | α-Amylase inhibition amylase assay defensin mustard aphid pest management |
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