%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Elleuch, J.
%A Jaoua, S.
%A Ginibre, Carole
%A Chandre, Fabrice
%A Tounsi, S.
%A Zghal, R. Z.
%T Toxin stability improvement and toxicity increase against dipteran and lepidopteran larvae of Bacillus thuringiensis crystal protein Cry2Aa
%D 2016
%L fdi:010068318
%G ENG
%J Pest Management Science
%@ 1526-498X
%K P20 helper protein ; Cry2Aa toxin ; larvicidal activity improvement ; protection against excessive proteolysis
%M ISI:000386927800006
%N 12
%P 2240-2246
%R 10.1002/ps.4261
%U https://www.documentation.ird.fr/hor/fdi:010068318
%> https://www.documentation.ird.fr/intranet/publi/2016/11/010068318.pdf
%V 72
%W Horizon (IRD)
%X 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.
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