Presence of the storage seed protein vicilin in internal organs of larval Callosobruchus maculatus (Coleoptera: Bruchidae).
Variant vicilins (7S storage globulins) of cowpea seeds (Vigna unguiculata) are considered as the main resistance factor present in some African genotypes against the bruchid Callosobruchus maculatus. It has been suggested that the toxic properties of vicilins may be related to their recognition and interaction with glycoproteins and other membrane constituents along the digestive tract of the insect. However, the possibility of a systemic effect has not yet been investigated. The objective of this work was to study the fate of 7S storage globulins of V. unguiculata in several organs of larvae of the cowpea weevil C. maculatus. Results demonstrated binding of vicilins to brush border membrane vesicles, suggesting the existence of specific receptors. Vicilins were detected in the haemolymph, in the midgut, and in internal organs, such as fat body and malpighian tubules. There is evidence of accumulation of vicilins in the fat body of both larvae and adults. The absorption of vicilins and their presence in insect tissues parallels classical sequestration of secondary compounds.
Uchôa
Adriana F
AF
Laboratory of Protein and Peptide Biochemistry, Centre for Biosciences and Biotechnology, Universidade Estadual do Norte Fluminense Darcy Ribeiro, CEP 28013-600, Campos dos Goytacazes, RJ, Brazil.
DaMatta
Renato A
RA
Retamal
Claudio A
CA
Albuquerque-Cunha
José M
JM
Souza
Sheila M
SM
Samuels
Richard I
RI
Silva
Carlos P
CP
Xavier-Filho
José
J
D000818:Animals; D015153:Blotting, Western; D001517:Coleoptera / Q000254:growth & development* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005216:Fat Body / Q000378:metabolism; D006458:Hemolymph / Q000378:metabolism; D007150:Immunohistochemistry; D008317:Malpighian Tubules / Q000378:metabolism; D008871:Microvilli / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D055314:Seed Storage Proteins
D010940:Plant Proteins; D055314:Seed Storage Proteins; C015575:vicilin protein, plant