Ultra-structure and histochemistry of digestive cells of Podisus nigrispinus (Hemiptera: Pentatomidae) fed with prey reared on bt-cotton

• Published in: Micron (Oxford, England : 1993) England : 1993), 2012-02, Vol.43 (2), p.245-250
• Main Authors: da Cunha, Franklin M., Caetano, Flávio H., Wanderley-Teixeira, Valéria, Torres, Jorge B., Teixeira, Álvaro A.C., Alves, Luiz C.
• Format: Article
• Language: English
• Subjects: Animals; Bacillus thuringiensis; bacterial proteins; Bacterial Proteins - genetics; Bacterial Proteins - toxicity; calcium; cotton; crops; Diet; electron microscopy; Endotoxins - genetics; Endotoxins - toxicity; Epithelial Cells - drug effects; Epithelial Cells - ultrastructure; Gastrointestinal Tract - cytology; Gastrointestinal Tract - drug effects; glycogen; Gossypium - genetics; Gossypium - toxicity; granules; Hemiptera; Hemolysin Proteins - genetics; Hemolysin Proteins - toxicity; Heteroptera - drug effects; histochemistry; Histocytochemistry; Histology; insects; instars; lipids; Microscopy, Electron; microvilli; midgut; Morphology; parasitoids; Plants, Genetically Modified - genetics; Plants, Genetically Modified - toxicity; Podisus nigrispinus; predation; Predator; predators; rearing; Spodoptera - drug effects; Spodoptera frugiperda; Sudan; Sudan dyes; toxicity; Transgenic plant; transgenic plants; ultrastructure
• ISSN: 0968-4328; 1878-4291
• DOI: 10.1016/j.micron.2011.08.006

► We analyzed the ultrastructure and histochemistry of the digestive cells of Podisus nigrispinus fed Spodoptera frugiperda reared on transgenic cotton. ► The results showed ultrastructural changes in the digestive cells, and modification in the distribution pattern of lipids, glycogen and calcium in these cells. The toxic effects of Bt proteins from the body of the prey/host to predators and parasitoids have been investigated as a route of impact on non-target insects of Bt crops. This research aimed to analyze ultrastructural changes and histochemistry in digestive cells of the middle region of the midgut of Podisus nigrispinus fed, since its second instar, with Spodoptera frugiperda reared on Bt cotton variety Acala90 B, which expresses the toxin Cry 1Ac, and its non-Bt isoline Acala 90. Fragments of the midgut of P. nigrispinus were analyzed by electron microscopy. For the histochemical analysis, Bromophenol Blue, Periodic Acid Schiff von Kossa, Alcian Blue pH 2.5 and Sudan Black were used. The Cry1Ac toxin of Bt cotton ingested by S. frugiperda promotes a disorganization in the perimicrovillar matrix of P. nigrispinus (third trophic level), thus generating ultrastructural changes in the digestive cells, as elongation of microvilli, presence of spherocrystals and granules of different electron densities, in addition to altering the distribution pattern of glycogen, lipids and calcium of these cells in the median region of the midgut. Thus, we conclude that species moderately susceptible to Cry1Ac toxin, such as S. frugiperda, can acquire this toxin and expose it to P. nigrispinus, which can interfere with your ability to predation.