Abstract
The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra x maximowiczii) expressing a mouse Orn decarboxylase (odc) cDNA. The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells. Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation. The addition of urea and glutamine had no effect on polyamines in either of the cell lines. Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells, (b) accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity, (c) Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine, (d) Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells, and (e) assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production.
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Claims 14
Claim · model-written summary
Transgenic poplar cells expressing mouse ODC showed elevated mouse ODC enzyme activity compared with NT cells.
- Material
- transgenic cellse1
- Treatment
- mouse Orn decarboxylase (odc) cDNAe0
- Outcome
- mouse ODC enzyme activitye1
- Direction
- elevatede1
- Comparator
- NT cellse1
PopulusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e0“expressing a mouse Orn decarboxylase (odc) cDNA”
e1“The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells”
Claim · model-written summary
Transgenic poplar cells had severalfold higher putrescine amounts than NT cells.
- Material
- transgenic cellse1
- Treatment
- mouse Orn decarboxylase (odc) cDNAe0
- Outcome
- amounts of putrescinee1
- Direction
- highere1
- Value
- severalfolde1
- Comparator
- NT cellse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e0“expressing a mouse Orn decarboxylase (odc) cDNA”
e1“The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells”
Claim · model-written summary
Transgenic poplar cells had a small increase in spermidine compared with NT cells.
- Material
- transgenic cellse1
- Treatment
- mouse Orn decarboxylase (odc) cDNAe0
- Outcome
- spermidinee1
- Direction
- increasee1
- Value
- smalle1
- Comparator
- NT cellse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e0“expressing a mouse Orn decarboxylase (odc) cDNA”
e1“The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells”
Claim · model-written summary
Transgenic poplar cells had a small reduction in spermine compared with NT cells.
- Material
- transgenic cellse1
- Treatment
- mouse Orn decarboxylase (odc) cDNAe0
- Outcome
- sperminee1
- Direction
- reductione1
- Value
- smalle1
- Comparator
- NT cellse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e0“expressing a mouse Orn decarboxylase (odc) cDNA”
e1“The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells”
Claim · model-written summary
Conversion of labeled ornithine into putrescine was significantly higher in transgenic than NT poplar cells.
- Treatment
- transgenice2
- Outcome
- conversion of labeled ornithine (Orn) into putrescinee2
- Direction
- highere2
- Comparator
- NT cellse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e2“The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells”
Claim · model-written summary
Exogenously supplied Orn increased cellular putrescine in both poplar cell lines.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e3“Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation”
Claim · model-written summary
High concentrations of arginine were inhibitory to putrescine accumulation in poplar cells.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e3“Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation”
Claim · model-written summary
Urea and glutamine had no effect on polyamines in either poplar cell line.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e4“The addition of urea and glutamine had no effect on polyamines in either of the cell lines”
Claim · model-written summary
Inhibition of glutamine synthetase by methionine sulfoximine substantially reduced putrescine and spermidine in both poplar cell lines.
- Treatment
- methionine sulfoximinee5
- Gene
- glutamine synthetasee5
- Outcome
- putrescine and spermidinee5
- Direction
- reductione5
- Value
- substantiale5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e5“Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines”
Claim · model-written summary
The authors conclude that transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in poplar cells.
- Outcome
- modulate putrescine metabolisme6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e6“Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells”
Claim · model-written summary
Accumulation of putrescine in high amounts does not affect native arginine decarboxylase activity in poplar cells.
- Treatment
- accumulation of putrescine in high amountse7
- Outcome
- native arginine decarboxylase activitye7
- Direction
- does not affecte7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e7“accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity”
Claim · model-written summary
Orn biosynthesis occurs primarily from glutamine/glutamate rather than from catabolic breakdown of arginine.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e7“Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine”
Claim · model-written summary
Orn biosynthesis may become a limiting factor for putrescine production in odc transgenic poplar cells.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e7“Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells”
Claim · model-written summary
Nitrogen assimilation into glutamine keeps pace with the increased demand for putrescine production.
- Compound
- glutaminee7
- Outcome
- assimilation of nitrogen into glutaminee7
- Qualifier
- keeps pace with an increased demand for its use for putrescine productione7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Poplar Cells”
e7“assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production”
The same questions in other papers
nitrogen · molecular: metabolites · Populus (poplar)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
1 paper more in this group
See all 5 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.