Abstract
S ummary Twenty‐one L‐amino acids and the amides L‐glutamine and L‐asparagine have been tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate. L‐ and D‐cystine were growth‐stimulatory. The amides, L‐aspartic acid and L‐arginine, did not significantly affect growth in concentrations up to 25 mg/1. The other amino acids were, to very differing extents, inhibitory to growth. The inhibitory activity of certain amino acids was greater at pH 6.8 than at 4.8. At this pH low concentrations of L‐arginine enhanced growth. The L‐ and D‐ forms of the amino acids differed in their inhibitory activity. With the exception of L‐glutamine and, to a lesser extent, of L‐asparagine and the natural forms of the dicarboxylic amino acids, all the amino acids tested as sole nitrogen sources for root growth were completely ineffective at both pH 4.8 and 6.8. This applied also to the ‘balanced’ mixtures of amino acids which had only low inhibitory activity when added to a nitrate‐containing medium. “Bacto’ casamino acids (an acid‐hydrolysed casein) was more effective than ammonium as a nitrogen source over the range pH 4.8 to 7.0, but was only as effective as nitrate at pH values close to neutrality. At pH values of 5.3 or above, the growth of excised tomato roots on ammonium was markedly stimulated by the addition of amino‐acid mixtures whose composition was based upon amino‐acid analyses of hydrolysed casein. A mixture of the basic amino acids only was almost as effective as more complex mixtures. At pH 6.8 ammonium plus a suitable amino‐acid mixture supported growth equal to that with the casamino acids. The very poor growth of excised tomato roots supplied with ammonium at pH 4.8 was, however, not significantly enhanced by the amino‐acid additions which were markedly stimulatory at higher pH values, and was inferior to growth with casamino acids at this pH. A high level of root growth cannot yet be achieved at pH 4.8 in the absence of nitrate.
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Claims 18
Claim · model-written summary
L- and D-cystine stimulated growth of excised tomato roots.
- Taxon
- tomato
Solanum lycopersicume0 - Treatment
- L‐ and D‐cystinee1
- Outcome
- growthe1
- Direction
- growth‐stimulatorye1
- Comparator
- standard amount of nitratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e1“L‐ and D‐cystine were growth‐stimulatory”
Claim · model-written summary
L-aspartic acid and L-arginine did not significantly affect tomato root growth at concentrations up to 25 mg/l.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- L‐aspartic acid and L‐argininee2
- Outcome
- growthe2
- Direction
- did not significantly affecte2
- Qualifier
- in concentrations up to 25 mg/1e2
- Comparator
- standard amount of nitratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e2“The amides, L‐aspartic acid and L‐arginine, did not significantly affect growth in concentrations up to 25 mg/1”
Claim · model-written summary
Most other amino acids were inhibitory to tomato root growth, to very differing extents.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- other amino acidse3
- Outcome
- growthe3
- Direction
- inhibitorye3
- Comparator
- standard amount of nitratee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e3“The other amino acids were, to very differing extents, inhibitory to growth”
Claim · model-written summary
The inhibitory activity of certain amino acids was greater at pH 6.8 than at pH 4.8.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- pH 6.8e4
- Outcome
- inhibitory activity of certain amino acidse4
- Direction
- greatere4
- Comparator
- pH 4.8e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e4“The inhibitory activity of certain amino acids was greater at pH 6.8 than at 4.8”
Claim · model-written summary
The L- and D- forms of the amino acids differed in their inhibitory activity.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- L‐ and D‐ forms of the amino acidse6
- Outcome
- inhibitory activitye6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e6“The L‐ and D‐ forms of the amino acids differed in their inhibitory activity”
Claim · model-written summary
Low concentrations of L-arginine enhanced tomato root growth at pH 6.8.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- low concentrations of L‐argininee5
- Outcome
- growthe5
- Direction
- enhancede5
- Qualifier
- At this pHe5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e5“At this pH low concentrations of L‐arginine enhanced growth”
Claim · model-written summary
L-glutamine, and to a lesser extent L-asparagine, were effective sole nitrogen sources for tomato root growth.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- L‐glutaminee7
- Outcome
- root growthe7
- Qualifier
- sole nitrogen sourcese7
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e7“With the exception of L‐glutamine and, to a lesser extent, of L‐asparagine and the natural forms of the dicarboxylic amino acids, all the amino acids tested as sole nitrogen sources for root growth were completely ineffective at both pH 4.8 and 6.8”
Claim · model-written summary
All other amino acids tested as sole nitrogen sources were completely ineffective for tomato root growth at pH 4.8 and 6.8.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- all the amino acids tested as sole nitrogen sourcese7
- Outcome
- root growthe7
- Direction
- completely ineffectivee7
- Qualifier
- at both pH 4.8 and 6.8e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e7“With the exception of L‐glutamine and, to a lesser extent, of L‐asparagine and the natural forms of the dicarboxylic amino acids, all the amino acids tested as sole nitrogen sources for root growth were completely ineffective at both pH 4.8 and 6.8”
Claim · model-written summary
Balanced amino-acid mixtures had only low inhibitory activity in a nitrate-containing medium.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- mixtures of amino acidse1
- Outcome
- inhibitory activitye1
- Direction
- lowe1
- Comparator
- nitrate‐containing mediume1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e1“mixtures of amino acids which had only low inhibitory activity when added to a nitrate‐containing medium”
Claim · model-written summary
Casamino acids were more effective than ammonium as a nitrogen source across pH 4.8 to 7.0.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- casamino acidse2
- Outcome
- effectivee2
- Direction
- more effectivee2
- Qualifier
- over the range pH 4.8 to 7.0e2
- Comparator
- ammoniume2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e2“casamino acids (an acid‐hydrolysed casein) was more effective than ammonium as a nitrogen source over the range pH 4.8 to 7.0”
Claim · model-written summary
Casamino acids were only as effective as nitrate near neutral pH.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- casamino acidse2
- Outcome
- effectivee3
- Direction
- only as effectivee3
- Qualifier
- at pH values close to neutralitye3
- Comparator
- nitratee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e2“casamino acids (an acid‐hydrolysed casein) was more effective than ammonium as a nitrogen source over the range pH 4.8 to 7.0”
e3“but was only as effective as nitrate at pH values close to neutrality”
Claim · model-written summary
At pH 5.3 or above, amino-acid mixtures markedly stimulated tomato root growth on ammonium.
- Taxon
- tomatoSolanum lycopersicume4
- Treatment
- addition of amino‐acid mixturese4
- Outcome
- growthe4
- Direction
- markedly stimulatede4
- Qualifier
- At pH values of 5.3 or abovee4
- Comparator
- ammoniume4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“At pH values of 5.3 or above, the growth of excised tomato roots on ammonium was markedly stimulated by the addition of amino‐acid mixtures”
Claim · model-written summary
A mixture of the basic amino acids only was almost as effective as more complex amino-acid mixtures.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- A mixture of the basic amino acids onlye5
- Outcome
- effectivee5
- Direction
- almost as effectivee5
- Comparator
- more complex mixturese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e5“A mixture of the basic amino acids only was almost as effective as more complex mixtures”
Claim · model-written summary
At pH 6.8, ammonium plus an amino-acid mixture supported tomato root growth equal to that with casamino acids.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- ammonium plus a suitable amino‐acid mixturee6
- Outcome
- growthe6
- Direction
- equale6
- Qualifier
- At pH 6.8e6
- Comparator
- casamino acidse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e6“At pH 6.8 ammonium plus a suitable amino‐acid mixture supported growth equal to that with the casamino acids”
Claim · model-written summary
Amino-acid additions did not significantly enhance the very poor growth on ammonium at pH 4.8.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- amino‐acid additionse7
- Outcome
- growthe7
- Direction
- not significantly enhancede7
- Qualifier
- at pH 4.8e7
- Comparator
- ammoniume7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e7“The very poor growth of excised tomato roots supplied with ammonium at pH 4.8 was, however, not significantly enhanced by the amino‐acid additions which were markedly stimulatory at higher pH values, and was inferior to growth with casamino acids at this pH”
Claim · model-written summary
Growth on ammonium at pH 4.8 was inferior to growth with casamino acids.
- Taxon
- tomatoSolanum lycopersicume0
- Treatment
- ammoniume7
- Outcome
- growthe7
- Direction
- inferiore7
- Qualifier
- at this pHe7
- Comparator
- casamino acidse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e7“The very poor growth of excised tomato roots supplied with ammonium at pH 4.8 was, however, not significantly enhanced by the amino‐acid additions which were markedly stimulatory at higher pH values, and was inferior to growth with casamino acids at this pH”
Claim · model-written summary
Tomato root growth on ammonium at pH 4.8 was very poor.
- Taxon
- tomatoSolanum lycopersicume0
- Outcome
- growthe7
- Qualifier
- supplied with ammonium at pH 4.8e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e7“The very poor growth of excised tomato roots supplied with ammonium at pH 4.8 was, however, not significantly enhanced by the amino‐acid additions which were markedly stimulatory at higher pH values, and was inferior to growth with casamino acids at this pH”
Claim · model-written summary
A high level of root growth cannot be achieved at pH 4.8 without nitrate.
- Taxon
- tomatoSolanum lycopersicume0
- Outcome
- high level of root growthe1
- Qualifier
- in the absence of nitratee1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tested for their effects on the growth of excised tomato roots, by adding them singly to a medium of pH 4.8 containing the standard amount of nitrate”
e1“A high level of root growth cannot yet be achieved at pH 4.8 in the absence of nitrate”
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