Abstract
The Cry23Aa/Cry37Aa proteins from Bacillus thuringiensis (Bt) have been described toxic to Cylas puncticollis larvae. In general, it is believed that Cry23Aa and Cry37Aa act jointly to exert the insecticidal activity, while there is no evidence of their toxicity individually. Therefore, in the present study, the contribution of each protein in the insecticidal activity toward C. puncticollis larvae has been assessed. The results showed that both proteins were toxic for C. puncticollis larvae when tested individually. Contrary to what was claimed previously, our results suggest that the presence of both proteins is not necessary to exert toxicity against C. puncticollis larvae. Also, the binding behavior of Cry23Aa protein to midgut receptors of C. puncticollis larvae has been determined. According to our results, Cry23Aa binds to C. puncticollis brush border membrane vesicles (BBMV) specifically and independently of Cry37Aa. Due to the lack of common binding sites, Cry23Aa can be pyramided with Cry3Aa protein for better management of C. puncticollis.
Highlights
Sweet potato, Ipomoea batatas L., is one of the mostly grown crops in Africa
An early study (Ekobu et al, 2010) showed that solubilized Cry23Aa/Cry37Aa proteins were toxic to C. puncticollis larvae
In order to be able to individually study the toxic activities of the two constituent proteins which are present in the crystal produced by the B. thuringiensis strain EG10327 toward this insect pest, the genes encoding for the Cry23Aa and Cry37Aa proteins were individually produced in the E. coli strain BL21 and tested against second instar larvae of C. puncticollis
Summary
Ipomoea batatas L., is one of the mostly grown crops in Africa. Several serious biotic and abiotic factors threaten the sweet potato production. Cylas puncticollis Boheman (Coleoptera: Brentidae), is one of the most economically important sweet potato insect pests in Africa (Chalfant et al, 1990). The high infestation percent of sweet potato to Cylas spp. resulted in a dramatic reduction of the tuber yield and a high percentage of unmarketable crops (Sorensen, 2009). Tremendous economic losses occur when Cylas spp. larvae tunnel inside the sweet potatoes, subsequently the occurrence of microbial contamination and terpenoid odor production (Smit et al, 1997). Due to the importance of this tuber crop in human consumption, livestock feed, and industrial production (Hazra et al, 2011), finding an appropriate strategy in controlling C. puncticollis is highly demanded
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
