Abstract
Leaf growth of many plant species shows rapid changes in response to alterations of the form and the level of N supply. In hydroponically-grown tomato (Lycopersicon esculentum L.), leaf growth was rapidly stimulated by NO(3)(-) application to NH(4)(+) precultured plants, while NH(4)(+) supply or complete N deprivation to NO(3)(-) precultured plants resulted in a rapid inhibition of leaf growth. Just 10 microM NO(3)(-) supply was sufficient to stimulate leaf growth to the same extent as 2 mM. Furthermore, continuous NO(3)(-) supply induced an oscillation of leaf growth rate with a 48 h interval. Since changes in NO(3)(-) levels in the xylem exudate and leaves did not correlate with NO(3)(-)-induced alterations of leaf growth rate, additional signals such as phytohormones may be involved. Levels of a known inhibitor of leaf growth, abscisic acid (ABA), did not consistently correspond to leaf growth rates in wild-type plants. Moreover, leaf growth of the ABA-deficient tomato mutant flacca was inhibited by NH(4)(+) without an increase in ABA concentration and was stimulated by NO(3)(-) despite its excessive ethylene production. These findings suggest that neither ABA nor ethylene are directly involved in the effects of N form on leaf growth. However, under all experimental conditions, stimulation of leaf growth by NO(3)(-) was consistently associated with increased concentration of the physiologically active forms of cytokinins, zeatin and zeatin riboside, in the xylem exudate. This indicates a major role for cytokinins as long-distance signals mediating the shoot response to NO(3)(-) perception in roots.
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Claims 10
Claim · model-written summary
Nitrate rapidly stimulated leaf growth in ammonium-precultured tomato.
- Taxon
- tomato
Solanum lycopersicume1 - Treatment
- NO(3)(-) applicatione0
- Outcome
- leaf growthe0
- Direction
- stimulatede0
- Comparator
- NH(4)(+) precultured plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf growth was rapidly stimulated by NO(3)(-) application to NH(4)(+) precultured plants”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Ammonium supply rapidly inhibited leaf growth in nitrate-precultured tomato.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- NH(4)(+) supplye0
- Outcome
- leaf growthe0
- Direction
- inhibitione0
- Comparator
- NO(3)(-) precultured plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NH(4)(+) supply or complete N deprivation to NO(3)(-) precultured plants resulted in a rapid inhibition of leaf growth”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Complete nitrogen deprivation rapidly inhibited leaf growth in nitrate-precultured tomato.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- complete N deprivatione0
- Outcome
- leaf growthe0
- Direction
- inhibitione0
- Comparator
- NO(3)(-) precultured plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NH(4)(+) supply or complete N deprivation to NO(3)(-) precultured plants resulted in a rapid inhibition of leaf growth”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Ten micromolar nitrate stimulated leaf growth as much as 2 mM nitrate.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- 10 microM NO(3)(-) supplye0
- Outcome
- leaf growthe0
- Direction
- stimulatee0
- Comparator
- 2 mMe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“10 microM NO(3)(-) supply was sufficient to stimulate leaf growth to the same extent as 2 mM”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Continuous nitrate supply produced 48-hour oscillations in tomato leaf growth rate.
- Taxon
- tomatoSolanum lycopersicume1
- Treatment
- continuous NO(3)(-) supplye0
- Outcome
- leaf growth ratee0
- Direction
- oscillatione0
- Value
- 48 he0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“continuous NO(3)(-) supply induced an oscillation of leaf growth rate with a 48 h interval”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Nitrate levels in xylem exudate and leaves did not correlate with nitrate-induced leaf growth changes.
- Taxon
- tomatoSolanum lycopersicume1
- Organ / stage
- leavese0
- Outcome
- leaf growth ratee0
- Direction
- did not correlatee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“changes in NO(3)(-) levels in the xylem exudate and leaves did not correlate with NO(3)(-)-induced alterations of leaf growth rate”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Abscisic acid levels did not consistently correspond to leaf growth rates in wild-type tomato.
- Taxon
- tomatoSolanum lycopersicume1
- Material
- wild-type plantse0
- Compound
- abscisic acid (ABA)e0
- Outcome
- leaf growth ratese0
- Direction
- did not consistently corresponde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“abscisic acid (ABA), did not consistently correspond to leaf growth rates in wild-type plants”
e1“tomato (Lycopersicon esculentum L.)”
Claim · model-written summary
Ammonium inhibited leaf growth in the flacca tomato mutant without increasing abscisic acid.
- Taxon
- tomatoSolanum lycopersicume0
- Material
- flaccae0
- Treatment
- NH(4)(+)e0
- Compound
- ABAe0
- Outcome
- leaf growthe0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf growth of the ABA-deficient tomato mutant flacca was inhibited by NH(4)(+) without an increase in ABA concentration”
Claim · model-written summary
Nitrate stimulated leaf growth in flacca despite excessive ethylene production.
- Taxon
- tomatoSolanum lycopersicume0
- Material
- flaccae0
- Treatment
- NO(3)(-)e1
- Compound
- ethylenee1
- Outcome
- leaf growthe0
- Direction
- stimulatede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf growth of the ABA-deficient tomato mutant flacca”
e1“was stimulated by NO(3)(-) despite its excessive ethylene production”
Claim · model-written summary
Nitrate-induced leaf growth stimulation consistently accompanied higher active cytokinin concentrations in xylem exudate.
- Taxon
- tomatoSolanum lycopersicume1
- Organ / stage
- xylem exudatee0
- Compound
- cytokinins, zeatin and zeatin ribosidee0
- Outcome
- leaf growthe0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“stimulation of leaf growth by NO(3)(-) was consistently associated with increased concentration of the physiologically active forms of cytokinins, zeatin and zeatin riboside, in the xylem exudate”
e1“tomato (Lycopersicon esculentum L.)”
The same questions in other papers
nitrogen · growth · Solanum lycopersicum (tomato)Positive and negative results
44 papers in the same direction as this paper · 108 in the opposite direction
- negative
- positive
- positive
149 papers more in this group
See all 153 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.