DNA insert from vector pSIM1278
This DNA insert comprises two expression cassettes that were
inserted into the pSIM1278 transformation vector.
The first cassette comprises fragments of both the asparagine
synthetase-1 gene (Asn1) and the polyphenol oxidase-5 gene (Ppo5),
arranged as inverted repeats between the Agp promoter of the
ADP glucose pyrophosphorylase gene (Agp) and the Gbss
promoter of the granule-bound starch synthase gene (Gbss) and
results in silencing of both the Ppo5 and Asn1 genes.
The second cassette is comprised of fragments of the promoters of
the starch associated gene (R1) and the phosphorylase-L gene (PhL),
operably linked to the same Agp and Gbss promoters as the first
cassette. The function of the second cassette is to silence the
promoters of the starch associated gene (R1) and the
phosphorylase-L gene (PhL).
Molecular analyses indicated that the transformed organism contains
a single nearly complete copy of the DNA insert at a single locus
and no vector backbone in the LMO. Alignment of the integration
site sequences to the MSU potato reference genome indicates the
likely integration site is on chromosome 8 for pSIM1278. There are
no ORFs covering the left junction associated with the pSIM1278
insert in X17. A single ORF was identified spanning the right
junction. It is almost completely native potato sequence.
DNA insert from vector pSIM1678
This DNA insert comprises two expression cassettes that were
inserted into the pSIM1678 transformation vector.
The first cassette comprises of the Rpi-vnt1 expression cassette,
which consists of the VNT1 protein
coding region regulated by the native Rpi-vnt1 promoter and
terminator sequences. VNT1 is an R-protein from the wild Solanum
species, S. venturii, which functions in the recognition of P.
infestans and elicits a hypersensitive response in potato,
conferring resistance to late blight disease.
The second insert consists of a down-regulation cassette for the
plant vacuolar invertase gene, VInv, consisting of sequence from
the potato VInv gene arranged as an inverted repeat and flanked by
opposing plant promoters, pGbss and pAgp. Vacuolar invertase
converts sucrose into glucose and fructose. Its down regulation
prevents excess darkening during frying and contributes to low
acrylamide potential
Molecular analyses indicated that the transformed organism contains
a single nearly complete copy of the DNA insert at a single locus
and no vector backbone in the LMO. Alignment of the integration
site sequences to the MSU potato reference genome indicates the
likely integration site is on chromosome 5 for pSIM1678. There are
no ORFs covering the left junction associated with the pSIM1678
insert in X17. A single ORF was identified spanning the right
junction. It is almost completely native potato sequence.
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None of the X17 junction ORFs were identified as homologs of known
toxins or allergens. Each X17 insert is shown to be stable during
vegetative propagation.
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