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Biochemical basis of insect resistance in inged bean ( Psophocarpus tetragonolobus ) seeds
Author(s) -
Gatehouse Angharad M R,
Hoe David S,
Flemming Joyce E,
Hilder Vaughan A,
Gatehouse John A
Publication year - 1991
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740550108
Subject(s) - callosobruchus maculatus , biology , trypsin inhibitor , globulin , botany , insect , trypsin , pest analysis , enzyme , biochemistry , immunology
Mature seeds of the inged bean ( Psophocarpus tetragonolobus ) are toxic to developing larvae of a range of cosmopolitan storage Bruchidae of economic importance, including the copea seed eevil, Callosobruchus maculatus . Insect feeding trials ere carried out in hich protein fractions from seeds of inged bean ere incorporated at a range of concentrations into artificial seeds, and their effects upon development of C maculatus determined. Both albumin and globulin fractions ere toxic to the developing larvae and their toxicity correlated ith their haemagglutinating activity. Assay of Psophocarpin A, B and C fractions demonstrated Psophocarpin B to be the most insecticidal and to contain the highest haemagglutinating activity. Purified basic seed lectin as highly insecticidal to C maculatus larvae, ith an LC 50 value of c. 3·5 g kg −1 . The physiological level of this protein in inged bean seeds is sufficient to account for their resistance to attack by C maculatus . inged bean trypsin inhibitor as also purified and tested in artificial seeds against C maculatus. Hoever, even at concentrations in excess of tice the physiological concentration it had no deleterious effects upon development.