Abstract
When serial dilutions of a suspension of Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots, the formation of nodules in the initially susceptible region of the roots of both hosts was found to be linearly dependent on the log of the inoculum dosage until an optimum dosage was reached. Approximately 30- to 100-fold higher dosages were required to elicit half-maximal nodulation on cowpea than on soybean in the initially susceptible zone of the root. However, at optimal dosages, about six times as many nodules formed in this region on cowpea roots than on soybean roots. There was no appreciable difference in the apparent rate of nodule initiation on these two hosts nor in the number of inoculum bacteria in contact with the root. These results are consistent with the possibility that cowpea roots have a substantially higher threshold of response to symbiotic signals from the bacteria than do soybean roots. Storage of B. japonicum cells in distilled water for several weeks did not affect their viability or efficiency of nodule initiation on soybean. However, the nodulation efficiency of these same cells on cowpea diminished markedly over a 2 week period. These differential effects of water storage indicate that at least some aspects of signal production by the bacteria during nodule initiation are different on the two hosts. Mutants of B. japonicum 138 defective in synthesis of soybean lectin binding polysaccharide were defective in their efficiency of nodule initiation on soybean but not on cowpea. These results also suggest that B. japonicum may produce different substances to initiate nodules on these two hosts.
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Claims 9
Claim · model-written summary
Nodule formation in both hosts was linearly dependent on log inoculum dosage up to an optimum.
- Taxon
- soybean and cowpea
Glycine max
Vigna unguiculatae1 - Organ / stage
- rootse0
- Treatment
- inoculum dosagee0
- Interactor
- Bradyrhizobium japonicum strain 138
Bradyrhizobium japonicume1symbiont - Outcome
- formation of nodulese0
- Direction
- linearly dependente0
- Qualifier
- until an optimum dosage was reachede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the formation of nodules in the initially susceptible region of the roots of both hosts was found to be linearly dependent on the log of the inoculum dosage until an optimum dosage was reached.”
e1“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
Cowpea required 30- to 100-fold higher dosage than soybean for half-maximal nodulation.
- Taxon
- cowpeaVigna unguiculatae1
- Organ / stage
- roote0
- Interactor
- Bradyrhizobium japonicum strain 138Bradyrhizobium japonicume1symbiont
- Outcome
- half-maximal nodulatione0
- Direction
- highere0
- Value
- 30- to 100-folde0
- Comparator
- soybeane0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Approximately 30- to 100-fold higher dosages were required to elicit half-maximal nodulation on cowpea than on soybean in the initially susceptible zone of the root.”
e1“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
At optimal dosage, cowpea formed about six times as many nodules as soybean.
- Taxon
- cowpeaVigna unguiculatae1
- Organ / stage
- rootse0
- Interactor
- Bradyrhizobium japonicum strain 138Bradyrhizobium japonicume1symbiont
- Outcome
- nodules formede0
- Direction
- as manye0
- Value
- six timese0
- Qualifier
- at optimal dosagese0
- Comparator
- soybean rootse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at optimal dosages, about six times as many nodules formed in this region on cowpea roots than on soybean roots.”
e1“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
Nodule initiation rate did not appreciably differ between hosts.
- Taxon
- cowpeaVigna unguiculatae1
- Interactor
- Bradyrhizobium japonicum strain 138Bradyrhizobium japonicume1symbiont
- Outcome
- apparent rate of nodule initiatione0
- Direction
- no appreciable differencee0
- Comparator
- soybeane1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was no appreciable difference in the apparent rate of nodule initiation on these two hosts”
e1“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
Inoculum bacteria contacting roots did not appreciably differ between hosts.
- Taxon
- cowpeaVigna unguiculatae1
- Interactor
- Bradyrhizobium japonicum strain 138Bradyrhizobium japonicume1symbiont
- Outcome
- number of inoculum bacteria in contact with the roote0
- Direction
- no_changeinferrede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nor in the number of inoculum bacteria in contact with the root.”
e1“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
Water storage did not affect nodule initiation efficiency on soybean.
- Taxon
- soybeanGlycine maxe0
- Treatment
- Storage of B. japonicum cells in distilled water for several weekse0
- Interactor
- B. japonicumBradyrhizobium japonicume0symbiont
- Outcome
- efficiency of nodule initiatione0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Storage of B. japonicum cells in distilled water for several weeks did not affect their viability or efficiency of nodule initiation on soybean.”
Claim · model-written summary
Water storage diminished cowpea nodulation efficiency over two weeks.
- Taxon
- cowpeaVigna unguiculatae0
- Treatment
- Storage of B. japonicum cells in distilled watere1
- Interactor
- Bradyrhizobium japonicum strain 138Bradyrhizobium japonicume2symbiont
- Outcome
- nodulation efficiencye0
- Direction
- diminishede0
- Qualifier
- over a 2 week periode0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the nodulation efficiency of these same cells on cowpea diminished markedly over a 2 week period.”
e1“Storage of B. japonicum cells in distilled water for several weeks”
e2“Bradyrhizobium japonicum strain 138 were inoculated onto both soybean and cowpea roots”
Claim · model-written summary
B. japonicum mutants were defective in soybean nodule initiation.
- Taxon
- soybeanGlycine maxe0
- Interactor
- B. japonicum 138Bradyrhizobium japonicume0symbiont
- Outcome
- efficiency of nodule initiatione0
- Direction
- defectivee0
- Qualifier
- defective in synthesis of soybean lectin binding polysaccharidee0
- Comparator
- cowpeae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mutants of B. japonicum 138 defective in synthesis of soybean lectin binding polysaccharide were defective in their efficiency of nodule initiation on soybean but not on cowpea.”
Claim · model-written summary
The same mutants were not defective in cowpea nodule initiation.
- Taxon
- cowpeaVigna unguiculatae0
- Interactor
- B. japonicum 138Bradyrhizobium japonicume0symbiont
- Outcome
- efficiency of nodule initiatione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Mutants of B. japonicum 138 defective in synthesis of soybean lectin binding polysaccharide were defective in their efficiency of nodule initiation on soybean but not on cowpea.”
The same questions in other papers
Bradyrhizobium japonicum · symbiosis · Glycine max (soybean)Positive and negative results
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3 papers in the same direction as this paper · 1 in the opposite direction
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- negative
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See all 5 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.