Abstract
A tobacco nitrite reductase (NiR) cDNA and its corresponding gene were isolated from cDNA and genomic libraries. An NiR antisense mRNA was expressed in transgenic tobacco under the control of a double 35S promoter. Transformants were obtained on a medium containing ammonium as the sole source of nitrogen. One plant growing normally on ammonium but displaying drastically reduced development and chlorotic leaves when grown on nitrate as the sole source of nitrogen was studied further. This plant accumulated nitrite fivefold over wild-type level and showed reduced amounts of ammonium (11% wild-type level), glutamine (19%), and total protein (8%). NiR mRNA and activity were below detectable levels. Under these conditions, nitrate reductase (NR) activity and mRNA were overexpressed, suggesting that N-metabolites resulting from nitrate reduction are responsible for the repression of the expression of the NR gene, independently from the presence or absence of a functional NR protein.
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 10
Claim · model-written summary
A tobacco NiR cDNA and gene were isolated.
- Taxon
- tobacco
Nicotiana tabacume0 - Gene
- nitrite reductase (NiR)e0
- Outcome
- cDNA and its corresponding gene were isolatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A tobacco nitrite reductase (NiR) cDNA and its corresponding gene were isolated”
Claim · model-written summary
The antisense tobacco plant grew normally on ammonium.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- ammoniume0
- Outcome
- growing normallye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“One plant growing normally on ammonium”
t0“tobacco”
Claim · model-written summary
The antisense plant had reduced development and chlorotic leaves on nitrate.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- nitrate as the sole source of nitrogene0
- Outcome
- development and chlorotic leavese0
- Direction
- drastically reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“displaying drastically reduced development and chlorotic leaves when grown on nitrate as the sole source of nitrogen”
t0“tobacco”
Claim · model-written summary
Nitrite accumulated fivefold over wild type.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- nitritee0
- Direction
- accumulatede0
- Value
- fivefolde0
- Comparator
- wild-type levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This plant accumulated nitrite fivefold over wild-type level”
t0“tobacco”
Claim · model-written summary
Ammonium fell to 11% of wild-type level.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- ammoniume0
- Direction
- reducede0
- Value
- 11%e0
- Comparator
- wild-type levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“showed reduced amounts of ammonium (11% wild-type level)”
t0“tobacco”
Claim · model-written summary
Glutamine fell to 19% of wild type.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- glutaminee0
- Direction
- reducede0
- Value
- 19%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“showed reduced amounts of ammonium (11% wild-type level), glutamine (19%)”
t0“tobacco”
Claim · model-written summary
Total protein fell to 8% of wild type.
- Taxon
- tobaccoNicotiana tabacumt0
- Outcome
- total proteine0
- Direction
- reducede0
- Value
- 8%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“showed reduced amounts of ammonium (11% wild-type level), glutamine (19%), and total protein (8%)”
t0“tobacco”
Claim · model-written summary
NiR mRNA and activity were below detection.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- NiRe0
- Outcome
- NiR mRNA and activity were below detectable levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NiR mRNA and activity were below detectable levels”
t0“tobacco”
Claim · model-written summary
Nitrate reductase activity and mRNA were overexpressed.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- nitrate reductase (NR)e0
- Outcome
- activity and mRNAe0
- Direction
- overexpressede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrate reductase (NR) activity and mRNA were overexpressed”
t0“tobacco”
Claim · model-written summary
The authors infer that nitrate-reduction metabolites repress NR expression independently of functional NR protein.
- Taxon
- tobaccoNicotiana tabacumt0
- Gene
- NR genee0
- Outcome
- repression of the expression of the NR genee0
- Qualifier
- N-metabolites resulting from nitrate reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N-metabolites resulting from nitrate reduction are responsible for the repression of the expression of the NR gene, independently from the presence or absence of a functional NR protein”
t0“tobacco”
The same questions in other papers
nitrogen · growth · Nicotiana tabacum (tobacco)Positive and negative results
16 papers in the same direction as this paper · 56 in the opposite direction
- positive
- positive
- positive
69 papers more in this group
See all 73 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.