Abstract
The effect of genetic alterations on carbon flow through the shikimate pathway, using gene amplification or antisense RNA expression, was examined. Transgenic potato plants containing a chimeric 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS) antisense gene were produced to examine the role(s) of DAHPS in plant development. Wound-induced DAHPS gene expression (enzyme activity, protein, and mRNA) was reduced in wounded tuber tissue of three independent transgenic plants expressing DAHPS antisense RNA. DAHPS mRNA levels were reduced in shoot tips and/or stem tissue of five antisense plants. These plants had reduced stem diameter and/or stem lignification compared to untransformed plants. These alterations may in part be due to reduced carbon flow through the shikimate pathway. Gene amplification allows an organism to increase the expression of a gene(s), particularly in response to environmental stress. The stability and expression of amplified 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) genes was examined in glyphosate resistant tobacco cells and regenerated plantlets. Resistant cells grown without glyphosate for over 3 years stably maintained high levels of EPSPS gene amplification; however, resistance to glyphosate declined 7-fold compared to cells continously grown on glyphosate. Similarly, plantlets regenerated from resistant cells retained levels of EPSPS gene amplification comparable to that in resistant cells, but resistance to glyphosate was greatly reduced. EPSPS mRNA levels in plantlets were reduced relative to those in resistant cells. Regenerated plantlets were altered morphologically; this was correlated with an increased genome size. The potential of utilizing gene amplification to increase the expression of nonselectable genes was examined. A transgenic petunia cell culture containing neomycin phosphotransferase II (npt II) and $\beta$-glucuronidase (GUS) genes was used in selection experiments to obtain kanamycin resistant cell lines. Resistance was correlated with npt II gene amplification and increased npt II mRNA levels. There was also a concurrent co-amplification of the linked GUS gene, resulting in increased GUS mRNA levels and enzyme activity. Amplified genes were stably maintained and GUS enzyme activity stably overexpressed in the absence of selective pressure. Amplification was found to occur within eleven growth cycles. In one cell line, gene amplification was accompanied by DNA rearrangement.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 14
Claim · model-written summary
DAHPS antisense reduced wound-induced expression in potato tuber tissue.
- Taxon
- potato
Solanum tuberosumt0 - Organ / stage
- wounded tuber tissuee0
- Treatment
- DAHPS antisense RNAe0
- Gene
- DAHPSe0
- Outcome
- DAHPS gene expressione0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Wound-induced DAHPS gene expression (enzyme activity, protein, and mRNA) was reduced in wounded tuber tissue of three independent transgenic plants expressing DAHPS antisense RNA.”
t0“potato”
Claim · model-written summary
DAHPS mRNA was reduced in shoot tips and/or stems of five antisense potato plants.
- Taxon
- potatoSolanum tuberosumt0
- Organ / stage
- shoot tips and/or stem tissuee0
- Gene
- DAHPSe0
- Outcome
- DAHPS mRNA levelse0
- Direction
- reducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DAHPS mRNA levels were reduced in shoot tips and/or stem tissue of five antisense plants.”
t0“potato”
Claim · model-written summary
Antisense potato plants had reduced stem diameter and/or lignification.
- Taxon
- potatoSolanum tuberosumt0
- Treatment
- antisense plantst1
- Outcome
- stem diameter and/or stem lignificatione0
- Direction
- reducede0
- Comparator
- untransformed plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These plants had reduced stem diameter and/or stem lignification compared to untransformed plants.”
t0“potato”
t1“antisense plants”
Claim · model-written summary
Tobacco cells retained high EPSPS gene amplification after over three years without glyphosate.
- Taxon
- tobacco
Nicotiana tabacumt0 - Gene
- EPSPSe0
- Outcome
- EPSPS gene amplificatione0
- Direction
- highe0
- Qualifier
- without glyphosate for over 3 yearse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Resistant cells grown without glyphosate for over 3 years stably maintained high levels of EPSPS gene amplification”
t0“tobacco”
Claim · model-written summary
Glyphosate resistance of tobacco cells grown without glyphosate declined sevenfold relative to continuously exposed cells.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- resistance to glyphosatee0
- Direction
- declinede0
- Value
- 7-folde0
- Comparator
- cells continously grown on glyphosatee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resistance to glyphosate declined 7-fold compared to cells continously grown on glyphosate.”
t0“tobacco”
Claim · model-written summary
Regenerated tobacco plantlets retained EPSPS amplification comparable to resistant cells.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- EPSPSe0
- Outcome
- EPSPS gene amplificatione0
- Comparator
- resistant cellse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plantlets regenerated from resistant cells retained levels of EPSPS gene amplification comparable to that in resistant cells”
t0“tobacco”
Claim · model-written summary
Regenerated tobacco plantlets had greatly reduced glyphosate resistance.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- resistance to glyphosatee0
- Direction
- greatly reducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resistance to glyphosate was greatly reduced.”
t0“tobacco”
Claim · model-written summary
EPSPS mRNA was lower in regenerated tobacco plantlets than resistant cells.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- EPSPSe0
- Outcome
- EPSPS mRNA levelse0
- Direction
- reducede0
- Comparator
- resistant cellse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“EPSPS mRNA levels in plantlets were reduced relative to those in resistant cells.”
t0“tobacco”
Claim · model-written summary
Regenerated tobacco plantlets had altered morphology correlated with increased genome size.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- genome sizee0
- Outcome
- altered morphologicallye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Regenerated plantlets were altered morphologically; this was correlated with an increased genome size.”
t0“tobacco”
Claim · model-written summary
Kanamycin resistance in petunia cells correlated with npt II amplification and increased npt II mRNA.
_flowers_in_Westgate_Gardens%2C_Canterbury.jpg?width=60){kind=small}
PetuniaNot reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_flowers_in_Westgate_Gardens%2C_Canterbury.jpg?width=500)
Verbatim
e0“Resistance was correlated with npt II gene amplification and increased npt II mRNA levels.”
t0“petunia”
Claim · model-written summary
Linked GUS co-amplification increased GUS mRNA and enzyme activity in petunia cells.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was also a concurrent co-amplification of the linked GUS gene, resulting in increased GUS mRNA levels and enzyme activity.”
t0“petunia”
Claim · model-written summary
Amplified genes and GUS overexpression persisted without selection in petunia cells.
- Gene
- GUSe0
- Outcome
- GUS enzyme activitye0
- Direction
- overexpressede0
- Qualifier
- absence of selective pressuree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Amplified genes were stably maintained and GUS enzyme activity stably overexpressed in the absence of selective pressure.”
t0“petunia”
Claim · model-written summary
Gene amplification occurred within eleven growth cycles in petunia cells.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Amplification was found to occur within eleven growth cycles.”
t0“petunia”
Claim · model-written summary
One petunia cell line showed DNA rearrangement with amplification.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In one cell line, gene amplification was accompanied by DNA rearrangement.”
t0“petunia”
The same questions in other papers
7-phospho-2-dehydro-3-deoxy-D-arabino-heptonic acid · molecular: expression · Solanum tuberosum (potato)Results agree
1 paper in the same direction as this paper
- negative
loss of function · molecular: expression · Solanum tuberosum (potato)Positive and negative results
10 papers in the same direction as this paper · 6 in the opposite direction
- positive
- positive
- positive
13 papers more in this group
See all 17 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.