A saline extract of hard winter wheat containing a-amylase inhibitors was fractionated by ammonium sulfate precipitation and chromatography on DEAE-Sephacel and BioGel P-100 Two amylase isozymes (Amy-l and Amy-2) from the rice weevil, Sitophilus oryzae (L.), differed in their sensitivity toward two fractions, P-100-1 and P-100-2, that eluted from the BioGel column. Inhibitor zymograms showed that P-I00-l and P-I00-2 were heterogeneous and contained at least four and seven proteins, respectively, with inhibitory activity against Amy-2. P-100-1 and P-I00-2 were further fractionated by high performance liquid chromatography on an Aquapore AX-300 column and analyzed by electrophoresis under dissociating and nondissociating conditions. Based on elution profiles from BioGel P-100 and results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, components of P-100-2 are apparently dimers. M, estimates of subunit size varied depending on denaturing conditions (14 kDa [kilodalton] by SDS-PAGE and 12 kDa with an SDS-PAGE system containing 8 M urea). Higher molecular weight inhibitors in P-100-1 dissociated into two components with M, values of 14 and 15 kDa by SDS-PAGE. A mechanism of action of these potential cereal resistance factors is postulated.
Document Type: Research Article
Publication date: December 1, 1989
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.