Elleuch J. auteur aut IRD Jaoua S. auteur aut IRD Ginibre Carole auteur aut IRD Chandre Fabrice auteur aut IRD Tounsi S. auteur aut IRD Zghal R. Z. auteur aut IRD text journalArticle eng text/pdf born digital access BACKGROUNDBacillus thuringiensis -endotoxins are the most widely used biopesticides for controlling economically important crop pests and disease vectors. Improving their efficacy is of great benefit. Here, an improvement in Cry2Aa-endotoxin toxicity was attempted via a cry gene over expression system using P20 from B. thuringiensis israelensis. RESULTSThe coexpression of Cry2Aa with P20 resulted in a seven fold increase in its production yield in B. thuringiensis. Generated crystals proved to be significantly more toxic (505.207 mu gg(-1), 1.99mgL(-1) and 1.49mgL(-1)) than the P20-lacking control (720.78 mu gg(-1), 705.69mgL(-1) and 508.51mgL(-1)) against Ephestia kuehniella, Aedes aegypti and Culex pipiens larvae respectively. In vitro, processing experiments revealed a P20-mediated protection of Cry2Aa against degradation under larval gut conditions. Thus, P20 could promote the maintenance of a tightly packaged conformation of Cry2Aa toxins in the larval midgut upon correct activation and binding to its membrane receptors. CONCLUSIONBased on their resistance against excessive proteolysis, Cry2Aa-endotoxins, produced in the presence of P20, could be considered as a successful control agent for E. kuehniella and an effective alternative for mosquito control, implying its possible exploitation in pest management programmes. specialized P20 helper protein Cry2Aa toxin larvicidal activity improvement protection against excessive proteolysis 052 076 020 084 72 12 2240-2246 2016 1526-498X https://www.documentation.ird.fr/hor/fdi:010068318 10.1002/ps.4261 1526-498X [F B010068318] https://www.documentation.ird.fr/hor/fdi:010068318 https://www.documentation.ird.fr/intranet/publi/2016/11/010068318.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-12-06 2017-08-23 fdi:010068318 fre