Characterization of an Argentine isolate of Bacillus thuringiensis similar to the HD-1 strain

• Autor(a) principal: Sauka,Diego H
• Data de Publicação: 2010
• Outros Autores: Basurto-Ríos,Regina E, Ibarra,Jorge E, Benintende,Graciela B
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Neotropical entomology (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2010000500016
• topic: Cryptic gene; cry1Ac; cry2Ab; Epinotia aporema

We report the characterization of an Argentine isolate of Bacillus thuringiensis (INTA TA24-6) similar to the HD-1 strain, which harbors a cryptic cry2Ab gene that apparently is transcribed but not translated into a protein. INTA TA24-6 showed a Rep-PCR pattern identical to the HD-1 strain, a plasmid pattern that resembled that of this strain and cry1 and cry2 genes as HD-1. Screening of cry1 and cry2 genes showed that INTA TA24-6 harbors only cry1Ac and cry2Ab genes. Furthermore, crystalline inclusions of INTA TA24-6 exhibit a bipyramidal shape, typical of Lepidoptera-active B. thuringiensis strains, containing a major protein of ca. 130 kDa toxic to Epinotia aporema Wals. (Lepidoptera: Tortricidae) larvae. Neither the flat-square to cuboidal crystal nor a ca. 65 kDa protein typical of strains expressing Cry2 proteins were detected in INTA TA24-6. In agreement with this information, parasporal crystals of INTA TA24-6 did not show toxicity to Aedes aegypti L. (Diptera:Culicidae) larvae. Gene transcription analyses suggested that the cry2A gene might be cryptic in INTA TA24-6 despite its transcription at different sporulation stages.