Abstract
The influence of stonewool substrate on the exudation of the major soluble carbon nutrients and of the auxin precursor tryptophane for Pseudomonas biocontrol agents was studied. To this end, the composition of the organic acids and sugars, as well that of tryptophane, of axenically collected exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper was determined. The major results were as follows. i) The total amount of organic acid is much higher than that of total sugar. ii) Exudation of both organic acids and sugars increases during plant growth. iii) Citric, succinic, and malic acids represent the major organic acids, whereas fructose and glucose are the major sugars. iv) Compared with glass beads as a neutral substrate, stonewool substantially stimulates exudation of organic acids and sugars. v) It appeared that enhanced root-tip-colonizing bacteria isolated previously from the rhizosphere of tomato and cucumber grow much better in minimal medium with citrate as the sole carbon source than other, randomly selected rhizobacteria do. This indicates that the procedure which selects for excellent root-tip colonizers enriches for strains which utilize the major exudate carbon source citrate. vi) The content of L-tryptophane, the direct precursor of auxin, is approximately 60-fold higher in seedling exudates of tomato and sweet pepper than in cucumber seedling exudates, indicating a higher possibility of plant growth stimulation after inoculation with auxin-producing rhizobacteria for tomato and sweet pepper crops than for cucumber. However, the biocontrol strain Pseudomonas fluorescens WCS365, which is able to convert tryptophane into auxin, did not stimulate growth of these three crops. In contrast, this strain did stimulate growth of roots of radish, a plant which exudes nine times more tryptophane than tomato does.
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Claims 10
Claim · model-written summary
Organic acid exudate amounts exceed sugar amounts.
- Taxon
- tomato, cucumber, and sweet pepper
Cucumis sativus
Capsicum annuum
Solanum lycopersicume2 - Outcome
- total amount of organic acide0
- Direction
- much highere0
- Comparator
- total sugare0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The total amount of organic acid is much higher than that of total sugar”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
Organic acid and sugar exudation increases during growth.
- Taxon
- tomato, cucumber, and sweet pepperCucumis sativusCapsicum annuumSolanum lycopersicume2
- Outcome
- Exudation of both organic acids and sugarse0
- Direction
- increasese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Exudation of both organic acids and sugars increases during plant growth”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
Citric, succinic and malic acids predominate among organic acids.
- Taxon
- tomato, cucumber, and sweet pepperCucumis sativusCapsicum annuumSolanum lycopersicume2
- Outcome
- Citric, succinic, and malic acids represent the major organic acidse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Citric, succinic, and malic acids represent the major organic acids”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
Fructose and glucose predominate among sugars.
- Taxon
- tomato, cucumber, and sweet pepperCucumis sativusCapsicum annuumSolanum lycopersicume2
- Outcome
- fructose and glucose are the major sugarse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fructose and glucose are the major sugars”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
Stonewool stimulates exudation relative to glass beads.
- Taxon
- tomato, cucumber, and sweet pepperCucumis sativusCapsicum annuumSolanum lycopersicume2
- Treatment
- stonewoole0
- Outcome
- exudation of organic acids and sugarse0
- Direction
- stimulatese0
- Comparator
- glass beadse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with glass beads as a neutral substrate, stonewool substantially stimulates exudation of organic acids and sugars”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
Selected root-tip colonizers grow better on citrate than random rhizobacteria.
- Taxon
- tomato and cucumberCucumis sativusSolanum lycopersicume0
- Interactor
- root-tip-colonizing bacteriae0other
- Outcome
- root-tip-colonizing bacteria isolated previously from the rhizosphere of tomato and cucumber growe0
- Direction
- much bettere0
- Qualifier
- citrate as the sole carbon sourcee0
- Comparator
- other, randomly selected rhizobacteriae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“enhanced root-tip-colonizing bacteria isolated previously from the rhizosphere of tomato and cucumber grow much better in minimal medium with citrate as the sole carbon source than other, randomly selected rhizobacteria do”
Claim · model-written summary
Tomato and sweet pepper seedling exudates contain about 60-fold more tryptophane than cucumber.
- Taxon
- tomato and sweet pepperCapsicum annuumSolanum lycopersicume0
- Organ / stage
- seedlinge0
- Outcome
- content of L-tryptophanee0
- Direction
- highere0
- Value
- approximately 60-folde0
- Comparator
- cucumber seedling exudatese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The content of L-tryptophane, the direct precursor of auxin, is approximately 60-fold higher in seedling exudates of tomato and sweet pepper than in cucumber seedling exudates”
Claim · model-written summary
P. fluorescens WCS365 did not stimulate growth of tomato, pepper or cucumber.
- Taxon
- tomato, cucumber, and sweet pepperCucumis sativusCapsicum annuumSolanum lycopersicume2
- Treatment
- Pseudomonas fluorescens WCS365e0
- Interactor
- Pseudomonas fluorescens WCS365
.JPG?width=60)
Pseudomonas fluorescense0biocontrol_agent - Outcome
- growth of these three cropse0
- Direction
- did not stimulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.JPG?width=500)
Verbatim
e0“Pseudomonas fluorescens WCS365, which is able to convert tryptophane into auxin, did not stimulate growth of these three crops”
t0“Vegetables Growing on Stonewool”
e2“exudates of seed, seedlings, and roots of tomato, cucumber, and sweet pepper”
Claim · model-written summary
P. fluorescens WCS365 stimulated radish root growth.
- Taxon
- radish
Raphanus sativuse0 - Treatment
- this straine0
- Interactor
- this straine0biocontrol_agent
- Outcome
- growth of roots of radishe0
- Direction
- stimulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this strain did stimulate growth of roots of radish, a plant which exudes nine times more tryptophane than tomato does”
Claim · model-written summary
Radish exudes nine times more tryptophane than tomato.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“radish, a plant which exudes nine times more tryptophane than tomato does”
The same questions in other papers
Pseudomonas fluorescens · growth · Cucumis sativus (cucumber)Positive and negative results
1 in the opposite direction
- positive
Pseudomonas fluorescens · growth · Solanum lycopersicum (tomato)Positive and negative results
1 paper in the same direction as this paper · 34 in the opposite direction
- positive
- positive
- positive
32 papers more in this group
See all 36 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.