Type 1 ribosome-inactivating proteins - entomotoxic, oxidative and genotoxic action on Anticarsia gemmatalis (Hübner) and Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae).
Ribosome-inactivating proteins (RIPs) from plants inhibit protein synthesis by inactivating ribosomes. Some two-chain (type 2) RIPs are highly toxic and may play a role in plant defense. The lower toxicity of single-chain (type 1) RIPs reflects the lack of a protein domain able to bind to, and translocate the toxin across cell membranes. We studied the effect of single-chain RIPs, lychnin, momordin, gelonin, PAP-S and saporin S-6, in larvae of Anticarsia gemmatalis and Spodoptera frugiperda. After ingesting a total dose of 20 or 40 microg of the toxins, weight gain, survival rate, lesions in DNA and oxidative status (catalase and superoxide dismutase activities and lipidic peroxidation) of RIP-treated insects were assayed. Momordin was the less toxic in the biossays. S. frugiperda had a more pronounced weight loss on the 4th day of treatment and A. gemmatalis on the 10th day. RIP-induced mortality reached 57.13% for A. gemmatalis and 29.45% for S. frugiperda. RIP-treated insects showed a 2-3-fold increase in DNA lesions as assessed by the comet assay, but there were no correlations between stress markers and DNA damage. We conclude that single-chain RIPs are entomotoxic to lepidopteran insects causing extensive DNA lesions.
Bertholdo-Vargas
Lúcia R
LR
Institute of Biotechnology, Universidade de Caxias do Sul, Rua Francisco Getúlio Vargas, 1130, CEP: 95070-560, Caxias do Sul, RS, Brazil.
Martins
Juliana Nascimento
JN
Bordin
Diana
D
Salvador
Mirian
M
Schafer
Alois Eduard
AE
Barros
Neiva Monteiro de
NM
Barbieri
Luigi
L
Stirpe
Fiorenzo
F
Carlini
Célia R
CR
D000818:Animals; D002374:Catalase / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000201:enzymology; D015227:Lipid Peroxidation; D009036:Moths / Q000187:drug effects* / Q000201:enzymology; D010940:Plant Proteins / Q000494:pharmacology; D054788:Ribosome Inactivating Proteins / Q000494:pharmacology; D054789:Ribosome Inactivating Proteins, Type 1 / Q000494:pharmacology*; D000076985:Saporins; D013482:Superoxide Dismutase / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
D010940:Plant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; C525537:lychnin; C470296:momordin I (protein); C025674:GEL protein, Gelonium multiflorum; D002374:Catalase; D013482:Superoxide Dismutase; D054788:Ribosome Inactivating Proteins; D000076985:Saporins; C024275:pokeweed antiviral protein