Abstract
SUMMARY The concentrations and composition of free amino acids in phloem sap from two cultivars of oats and barley, both susceptible to the aphid Rhopalosiphum padi , were determined by means of high performance liquid chromatography. Sap was collected from excised aphid stylets at three developmental stages (seedlings, tillering plants and plants undergoing stem elongation) from plants given or not given fertiliser and grown outdoors. In connection, the growth of individual R. padi nymphs was estimated at the same phenological stages on plants grown in the greenhouse. The content of free amino acids was consistently higher in seedlings than in plants at the early tillering stage. Only in seedlings did the addition of fertiliser increase amino acid levels. Barley phloem sap contained more free amino acids than that of oats when fertiliser was added and at later developmental stages. Phloem sap of oats and barley showed similar patterns in their composition of free amino acids at the seedling stage, but as the plants grew older the patterns became increasingly different. Plants given fertiliser had higher amounts of dicarboxylic amino acids (glutamic and aspartic acid) than unfertilised plants. The concentrations of γ‐amino butyric acid, glycine, histidine, and methionine were very low in all treatments. The relative growth rates of R. padi nymphs were low when amino acid content was low and vice versa. The results are discussed in relation to host plant suitability and plant resistance mechanisms.
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Claims 10
Claim · model-written summary
oat seedlings had higher phloem free amino acids than early tillering plants.
- Taxon
- oat
Avena sativat0 - Organ / stage
- seedlingse0
- Outcome
- free amino acidse0
- Direction
- highere0
- Comparator
- early tillering stagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“The content of free amino acids was consistently higher in seedlings than in plants at the early tillering stage.”
Claim · model-written summary
barley seedlings had higher phloem free amino acids than early tillering plants.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaret0 - Organ / stage
- seedlingse0
- Outcome
- free amino acidse0
- Direction
- highere0
- Comparator
- early tillering stagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“oat and barley”
e0“The content of free amino acids was consistently higher in seedlings than in plants at the early tillering stage.”
Claim · model-written summary
Fertiliser increased seedling amino acid levels in oats.
- Taxon
- oatAvena sativat0
- Organ / stage
- seedlingse0
- Treatment
- addition of fertilisere0
- Outcome
- amino acid levelse0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“Only in seedlings did the addition of fertiliser increase amino acid levels.”
Claim · model-written summary
Fertiliser increased seedling amino acid levels in barley.
- Taxon
- barleyHordeum vulgaret0
- Organ / stage
- seedlingse0
- Treatment
- addition of fertilisere0
- Outcome
- amino acid levelse0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“Only in seedlings did the addition of fertiliser increase amino acid levels.”
Claim · model-written summary
Fertilised barley sap contained more free amino acids than oat sap at later stages.
- Taxon
- BarleyHordeum vulgaree0
- Treatment
- fertilisere0
- Outcome
- free amino acidse0
- Direction
- moree0
- Comparator
- oatse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Barley phloem sap contained more free amino acids than that of oats when fertiliser was added and at later developmental stages.”
Claim · model-written summary
Oat and barley sap composition patterns diverged increasingly with age.
- Taxon
- oatsAvena sativae0
- Organ / stage
- seedling stagee0
- Outcome
- patterns in their composition of free amino acidse0
- Direction
- increasingly differente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phloem sap of oats and barley showed similar patterns in their composition of free amino acids at the seedling stage, but as the plants grew older the patterns became increasingly different.”
Claim · model-written summary
Fertilised oat had higher dicarboxylic amino acids.
- Taxon
- oatAvena sativat0
- Treatment
- fertilisere0
- Outcome
- dicarboxylic amino acidse0
- Direction
- highere0
- Comparator
- unfertilised plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“Plants given fertiliser had higher amounts of dicarboxylic amino acids (glutamic and aspartic acid) than unfertilised plants.”
Claim · model-written summary
Fertilised barley had higher dicarboxylic amino acids.
- Taxon
- barleyHordeum vulgaret0
- Treatment
- fertilisere0
- Outcome
- dicarboxylic amino acidse0
- Direction
- highere0
- Comparator
- unfertilised plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“Plants given fertiliser had higher amounts of dicarboxylic amino acids (glutamic and aspartic acid) than unfertilised plants.”
Claim · model-written summary
GABA, glycine, histidine and methionine concentrations were very low across treatments.
- Taxon
- barleyHordeum vulgaret0
- Outcome
- concentrations of γ‐amino butyric acid, glycine, histidine, and methioninee0
- Direction
- very lowe0
- Qualifier
- all treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“oat and barley”
e0“The concentrations of γ‐amino butyric acid, glycine, histidine, and methionine were very low in all treatments.”
Claim · model-written summary
R. padi nymph growth rates covaried with host amino acid content.
- Taxon
- oatAvena sativat0
- Organ / stage
- nymphse0
- Interactor
- R. padi
_Figure_1_a.jpg?width=60)
Rhopalosiphum padie0pest - Outcome
- relative growth rates of R. padi nymphse0
- Direction
- lowe0
- Qualifier
- when amino acid content was lowe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Figure_1_a.jpg?width=500)
Verbatim
t0“oat and barley”
e0“The relative growth rates of R. padi nymphs were low when amino acid content was low and vice versa.”
The same questions in other papers
fertilization · molecular: metabolites · Avena sativa (oats)Positive and negative results
8 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
6 papers more in this group
See all 10 papers →fertilization · molecular: metabolites · Hordeum vulgare (barley)Positive and negative results
37 papers in the same direction as this paper · 7 in the opposite direction · 2 reporting no difference from an alternative
- no effect
- negative
- no effect
43 papers more in this group
See all 47 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.