Most of the commercialized Bt crops express
cry genes under 35S promoter that induces strong gene... more Most of the commercialized Bt crops express cry genes under 35S promoter that induces strong gene expression in all plant parts. However, targeted foreign gene expression in plants is esteemed more important as public may be likely to accept ‘less intrusive’ expression of transgene. We developed plant expression constructs harboring cry1Ac gene under control of wound-inducible promoter (AoPR1) to confine Bt gene expression in insect wounding parts of the plants in comparison with cry1Ac gene under the control of 35S promoter. The constructs were used to transform four Turkish cotton cultivars (GSN- 12, STN-468, Ozbek-100 and Ayhan-107) through Agrobacterium tumefaciens strains GV2260 containing binary vectors p35SAcBAR.101 and AoPR1AcBAR.101 harboring cry1Ac gene under control of 35S and AoPR1, respectively. Phosphinothricin (PPT) was used at concentration of 5 mg L-1 for selection of primary transformants. The primary transformants were analyzed for transgene presence and expression standard molecular techniques. The transformants exhibited appreciable mortality rates against larvae of Spodoptera exigua and S. littoralis. It was found that mechanical wounding of T1 transgenic plants was effective in inducing expression of cry1Ac protein as accumulated levels of cry1Ac protein increased during post-wounding period. We conclude that use of woundinducible promoter to drive insecticidal gene(s) can be regarded as a valuable insect-resistant management strategy since the promoter activity is limited to insect biting sites of plant. There is no Bt toxin accumulation in unwounded plant organs, seed and crop residues, cotton products and by-products, thus minimizing food and environmental concerns.
Most of the commercialized Bt crops express
cry genes under 35S promoter that induces strong gene... more Most of the commercialized Bt crops express cry genes under 35S promoter that induces strong gene expression in all plant parts. However, targeted foreign gene expression in plants is esteemed more important as public may be likely to accept ‘less intrusive’ expression of transgene. We developed plant expression constructs harboring cry1Ac gene under control of wound-inducible promoter (AoPR1) to confine Bt gene expression in insect wounding parts of the plants in comparison with cry1Ac gene under the control of 35S promoter. The constructs were used to transform four Turkish cotton cultivars (GSN- 12, STN-468, Ozbek-100 and Ayhan-107) through Agrobacterium tumefaciens strains GV2260 containing binary vectors p35SAcBAR.101 and AoPR1AcBAR.101 harboring cry1Ac gene under control of 35S and AoPR1, respectively. Phosphinothricin (PPT) was used at concentration of 5 mg L-1 for selection of primary transformants. The primary transformants were analyzed for transgene presence and expression standard molecular techniques. The transformants exhibited appreciable mortality rates against larvae of Spodoptera exigua and S. littoralis. It was found that mechanical wounding of T1 transgenic plants was effective in inducing expression of cry1Ac protein as accumulated levels of cry1Ac protein increased during post-wounding period. We conclude that use of woundinducible promoter to drive insecticidal gene(s) can be regarded as a valuable insect-resistant management strategy since the promoter activity is limited to insect biting sites of plant. There is no Bt toxin accumulation in unwounded plant organs, seed and crop residues, cotton products and by-products, thus minimizing food and environmental concerns.
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cry genes under 35S promoter that induces strong gene
expression in all plant parts. However, targeted foreign
gene expression in plants is esteemed more important as
public may be likely to accept ‘less intrusive’ expression of
transgene. We developed plant expression constructs harboring cry1Ac gene under control of wound-inducible
promoter (AoPR1) to confine Bt gene expression in insect
wounding parts of the plants in comparison with cry1Ac
gene under the control of 35S promoter. The constructs
were used to transform four Turkish cotton cultivars (GSN-
12, STN-468, Ozbek-100 and Ayhan-107) through
Agrobacterium tumefaciens strains GV2260 containing
binary vectors p35SAcBAR.101 and AoPR1AcBAR.101
harboring cry1Ac gene under control of 35S and AoPR1,
respectively. Phosphinothricin (PPT) was used at concentration
of 5 mg L-1 for selection of primary transformants.
The primary transformants were analyzed for transgene
presence and expression standard molecular techniques.
The transformants exhibited appreciable mortality rates
against larvae of Spodoptera exigua and S. littoralis. It was
found that mechanical wounding of T1 transgenic plants
was effective in inducing expression of cry1Ac protein as
accumulated levels of cry1Ac protein increased during
post-wounding period. We conclude that use of woundinducible promoter to drive insecticidal gene(s) can be
regarded as a valuable insect-resistant management strategy
since the promoter activity is limited to insect biting
sites of plant. There is no Bt toxin accumulation in
unwounded plant organs, seed and crop residues, cotton
products and by-products, thus minimizing food and
environmental concerns.
cry genes under 35S promoter that induces strong gene
expression in all plant parts. However, targeted foreign
gene expression in plants is esteemed more important as
public may be likely to accept ‘less intrusive’ expression of
transgene. We developed plant expression constructs harboring cry1Ac gene under control of wound-inducible
promoter (AoPR1) to confine Bt gene expression in insect
wounding parts of the plants in comparison with cry1Ac
gene under the control of 35S promoter. The constructs
were used to transform four Turkish cotton cultivars (GSN-
12, STN-468, Ozbek-100 and Ayhan-107) through
Agrobacterium tumefaciens strains GV2260 containing
binary vectors p35SAcBAR.101 and AoPR1AcBAR.101
harboring cry1Ac gene under control of 35S and AoPR1,
respectively. Phosphinothricin (PPT) was used at concentration
of 5 mg L-1 for selection of primary transformants.
The primary transformants were analyzed for transgene
presence and expression standard molecular techniques.
The transformants exhibited appreciable mortality rates
against larvae of Spodoptera exigua and S. littoralis. It was
found that mechanical wounding of T1 transgenic plants
was effective in inducing expression of cry1Ac protein as
accumulated levels of cry1Ac protein increased during
post-wounding period. We conclude that use of woundinducible promoter to drive insecticidal gene(s) can be
regarded as a valuable insect-resistant management strategy
since the promoter activity is limited to insect biting
sites of plant. There is no Bt toxin accumulation in
unwounded plant organs, seed and crop residues, cotton
products and by-products, thus minimizing food and
environmental concerns.