Coexpression of Potato PVYo Coat Protein and cryV-Bt Genes in Potato

Abstract

<jats:p>The codon-modified <jats:italic>cryV-Bt</jats:italic> gene (<jats:italic>cryV-Bt</jats:italic>) from <jats:italic>Bacillus thuringiensis</jats:italic> subsp<jats:italic>. kurstaki</jats:italic> Berliner, which is specifically toxic to Lepidoptera and Coleoptera insects, and a potato virus Y<jats:sup>o</jats:sup> coat protein gene (<jats:italic>PVY<jats:sup>o</jats:sup>cp</jats:italic>), in which the aphid transmission site was inactivated, were cotransformed into potato (<jats:italic>Solanum tuberosum</jats:italic> L.) `Spunta' via <jats:italic>Agrobacterium tumefaciens</jats:italic> Conn. We demonstrated the integration and expression of both genes by molecular analysis and bioassays. All <jats:italic>cryV-Bt</jats:italic>/<jats:italic>PVY<jats:sup>o</jats:sup>cp</jats:italic>-transgenic lines were more resistant to potato tuber moth (<jats:italic>Phthorimaea operculella</jats:italic> Zeller) and PVY<jats:sup>o</jats:sup> infection than nontransgenic `Spunta'. Four <jats:italic>cryV-Bt</jats:italic>/<jats:italic>PVY<jats:sup>o</jats:sup>cp</jats:italic> transgenic lines were equal in potato tuber moth mortality to a <jats:italic>cryV-Bt</jats:italic> transgenic line, but of these four only two lines were equivalent in PVY<jats:sup>o</jats:sup> titer levels to a <jats:italic>PVY<jats:sup>o</jats:sup>cp</jats:italic>-transgenic line. We identified two transgenic lines, 6a-3 and 6a-5, which showed greater resistance to potato tuber moth and PVY<jats:sup>o</jats:sup> than the other <jats:italic>cryV-Bt</jats:italic>/<jats:italic>PVY<jats:sup>o</jats:sup>cp</jats:italic> transgenic lines. This study indicated that multiple genes, conferring insect pest resistance and virus resistance, could be engineered into and expressed simultaneously in a potato cultivar.</jats:p>

Expression of cry1Ac9 and cry9Aa2 genes under a potato light-inducible Lhca3 promoter in transgenic potatoes for tuber moth resistance

“…The bioassay method used was based on the assumption that the level of Cry protein in excised leaves was similar to that in the foliage of intact plants. The same assumption has been made in similar studies involving PTM bioassays (Ebora et al, 1994;Jansens et al, 1995;Westedt et al, 1998;Beuning et al, 2001;Douches et al, 1998Douches et al, , 2002Li et al, 1999;Davidson et al, 2002Davidson et al, , 2004, and has been validated by the observed high correlation between excised leaves and intact plants for growth of PTM larvae in response to cry gene expression (Davidson et al, 2002).…”

“…In potato, it is often desirable to couple high-level expression of the transgene in foliage with no expression in tubers. Constitutive promoters have been used to drive cry gene expression in all previous studies targeting PTM resistance in transgenic potatoes (Douches et al, , 2002Jansens et al, 1995;Cañedo et al, 1999;Li et al, 1999;Chakrabarti et al, 2000;Mohammed et al, 2000;Davidson et al, 2002Davidson et al, , 2004. Since PTM generally infests foliage of potato crops prior to the tubers (Foot, 1979), preventing foliar infestation may be sufficient to avoid tuber infestation.…”

“…Various management strategies such as cultural practices, biological and chemical control are used to manage PTM (Goldson & Emberson, 1985;Hanafi, 1999). To contribute an additional component to integrated pest management, the development of transgenic potatoes that express the insecticidal toxins produced by different strains of the soil bacterium, Bacillus thuringiensis (Bt), has been investigated (Jansens et al, 1995;Douches et al, 1998;Rico et al, 1998;Cañedo et al, 1999;Li et al, 1999;Chakrabarti et al, 2000;Davidson et al, 2002Davidson et al, , 2004.…”

“…The 35S promoter used for transcriptional control of the cry genes in previous investigations in potato Rico et al, 1998;Cañedo et al, 1999;Li et al, 1999;Chakrabarti et al, 2000;Davidson et al, 2002Davidson et al, , 2004 is well known to be constitutively expressed throughout plants (Odell et al, 1985), including potato (Gatehouse et al, 1997). However, it is often desirable to couple high-level expression of the transgene in potato foliage with no expression in tubers.…”

Potato Transformation with Modified Nucleotide Sequences of the cry9Aa2 Gene Improves Resistance to Potato Tuber Moth

“…To contribute an additional component to integrated pest management, the development of transgenic potatoes that express genes encoding insecticidal compounds has been investigated (Meiyalaghan et al 2005). The use of cry genes from the soil bacterium, Bacillus thuringiensis, has been especially successful (e.g., Jansens et al 1995;Douches et al 1998;Li et al 1999;Davidson et al 2002Davidson et al , 2004Meiyalaghan et al 2006). However, the transfer of native cry genes to plants has often resulted in inadequate gene expression.…”