Insecticidal Activity of the Protein Encoded by the cryV Gene of Bacillus thuringiensis kurstaki INA-02

Abstract

A new host specificity was discovered with the insecticidal protein encoded by the cryV gene. The cryV gene was cloned from the Bacillus thuringiensis kurstaki INA-02 strain, which was selected among a number of B. thuringiensis isolates because of its high activity against Spodoptera litura. Analyses by polymerase chain reaction (PCR) revealed that INA-02 contained the cryIA(a) and cryV genes. Since no Spodoptera activity was observed with B. thuringiensis sotto, which contained only cryIA(a), insecticidal activity of the protein encoded by the cryV gene was investigated with several insect species including S. litura. For bioassay, the cryV gene was highly expressed in an acrystalliferous B. thuringiensis strain, BT51. The CryV protein from BT51 was assayed against larvae of three lepidopteran species, Bombyx mori, S. litura, and Plutella xylostella. The protein was highly active against S. litura and P. xylostella, suggestive that the protein contributes to the unique activity of INA-02.

Discovery of a novel Bacillus thuringiensis Cry8D protein and the unique toxicity of the Cry8D-class proteins against scarab beetles

“…In order to express Cry8Db in Bt, cry8Db was cloned into a Bt expression vector as described by Sasaki et al (1996) and transferred in methylation-minus Escherichia coli GM2163 (New England Biolabs). Plasmid DNA from E. coli was introduced into an acrystalliferous Bt kurstaki HD-1 mutant, BT51 by electroporation (Yamamoto et al, 1988).…”

“…In order to express the cry8Db gene in Bt, the gene was cloned into a Bt expression vector (Sasaki et al, 1996) and transformed to BT51. BT51 which was transformed with the cry8Db gene was designated as BT51-8Db.…”

A Bacillus thuringiensis Cry protein controls soybean cyst nematode in transgenic soybean plants

“…For Bt expression, Cry14Ab was cloned into a Bt expression vector with a Cry1Ca promoter and a Cry1Ac terminator 24 , which was passed through a dam − / dcm − E. coli strain before being used to transform Bt Cultures were grown in CYS media with 10 µg/mL tetracycline. Sporulated cultures were pelleted, and Cry14Ab protein was extracted by sonication and shaking in 20 mM CAPS pH 10.5, 10 mM beta-mercaptoethanol, 10% glycerol.…”

Carboxy-terminal extension effects on crystal formation and insecticidal properties of Cry15Aa

“…The vector pSB629, and the shuttle vector pSB634 used in this study, have been described before (de Maagd et al, 1996;Sasaki et al, 1996) the cry15Aa gene and its truncated version between the cry1Ca promoter and cry1Ac terminator, the NcoI-BamI (cry1Ca) fragment of pSB629 was replaced by the NcoI-BamHI fragments of pSN63 (cry15Aa), and pSN73 (truncated cry15Aa). The resulting plasmids (pSN81 and pSN82) were digested with ApaI-SacI, and the expression cassettes were cloned into the ApaI-SacI sites of pSB634 giving pSN83 and pSN84 respectively.…”