Abstract
The effects of acidity on NO3 - absorption by nonnodulated, vegetative soybean (Glycine max [L.] Merrill) plants were examined during a 30-day growth period in flowing solution culture. The acidities of nutrient solutions were maintained at pH 6.1, 5.1, or 4.1 ± 0.1. Root growth rates were reduced for about 20 days by increasing acidity but then recovered to rates which exceeded those at low acidity so that root mass in all treatments was similar after 30 days. In contrast, the uptake rate of NO3 - per unit of root mass was enhanced by increased acidity within the first day of exposure to rates that remained constant throughout the treatment period. Total nitrate uptake and shoot growth rates were restricted at higher acidities until about day 20 and thereafter recovered to rates which exceeded those at low acidity in parallel with the recovery in root growth rates. Alterations in total NO3 - uptake in response to acidity also were evaluated in relation to changes in uptake of other ions and ionic balance in the plant tissue. As acidity increased, anion uptake was increased relative to cation uptake. Though greater reduction of NO3 -, and thus greater generation of internal OH- ions, occurred in plants at higher acidities, tissues contained smaller amounts of organic anions. Acidity of the root-zone, therefore, influenced partitioning of internal OH- generated during NO3 - reduction between synthesis of organic anions in the tissue and efflux to the external solution in association with excess anion uptake.
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Claims 12
Claim · model-written summary
Increasing acidity reduced soybean root growth rates for about 20 days.
- Taxon
- soybean
Glycine maxe1 - Treatment
- increasing aciditye0
- Outcome
- Root growth ratese0
- Direction
- reducede0
- Qualifier
- for about 20 dayse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root growth rates were reduced for about 20 days by increasing acidity”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
After about 20 days, root growth rates recovered and exceeded those at low acidity.
- Taxon
- soybeanGlycine maxe2
- Treatment
- increasing aciditye1
- Outcome
- Root growth ratese1
- Direction
- exceedede0
- Qualifier
- about 20 dayse1
- Comparator
- low aciditye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“then recovered to rates which exceeded those at low acidity”
e1“Root growth rates were reduced for about 20 days by increasing acidity”
e2“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
Root mass was similar across acidity treatments after 30 days.
- Taxon
- soybeanGlycine maxe1
- Outcome
- root masse0
- Direction
- similare0
- Qualifier
- after 30 dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“root mass in all treatments was similar after 30 days”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
Increasing acidity enhanced nitrate uptake rate per unit root mass within the first day, with rates remaining constant thereafter.
- Taxon
- soybeanGlycine maxe1
- Treatment
- increased aciditye0
- Outcome
- uptake rate of NO3 - per unit of root masse0
- Direction
- enhancede0
- Qualifier
- within the first day of exposuree0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the uptake rate of NO3 - per unit of root mass was enhanced by increased acidity within the first day of exposure to rates that remained constant throughout the treatment period”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
Higher acidity restricted total nitrate uptake until about day 20.
- Taxon
- soybeanGlycine maxe1
- Treatment
- higher aciditiese0
- Outcome
- Total nitrate uptakee0
- Direction
- restrictede0
- Qualifier
- until about day 20e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total nitrate uptake and shoot growth rates were restricted at higher acidities until about day 20”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
Higher acidity restricted shoot growth rates until about day 20.
- Taxon
- soybeanGlycine maxe1
- Treatment
- higher aciditiese0
- Outcome
- shoot growth ratese0
- Direction
- restrictede0
- Qualifier
- until about day 20e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total nitrate uptake and shoot growth rates were restricted at higher acidities until about day 20”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
After day 20, total nitrate uptake recovered and exceeded that at low acidity.
- Taxon
- soybeanGlycine maxe1
- Treatment
- higher aciditiese0
- Outcome
- Total nitrate uptakee0
- Direction
- exceedede0
- Qualifier
- thereaftere0
- Comparator
- low aciditye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total nitrate uptake and shoot growth rates were restricted at higher acidities until about day 20 and thereafter recovered to rates which exceeded those at low acidity”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
After day 20, shoot growth rates recovered and exceeded those at low acidity.
- Taxon
- soybeanGlycine maxe1
- Treatment
- higher aciditiese0
- Outcome
- shoot growth ratese0
- Direction
- exceedede0
- Qualifier
- thereaftere0
- Comparator
- low aciditye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total nitrate uptake and shoot growth rates were restricted at higher acidities until about day 20 and thereafter recovered to rates which exceeded those at low acidity”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
As acidity increased, anion uptake increased relative to cation uptake.
- Taxon
- soybeanGlycine maxe1
- Treatment
- acidity increasede0
- Outcome
- anion uptakee0
- Direction
- increasede0
- Comparator
- cation uptakee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“As acidity increased, anion uptake was increased relative to cation uptake”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
At higher acidity, soybean plants reduced more nitrate, generating more internal hydroxide ions.
- Taxon
- soybeanGlycine maxe1
- Treatment
- higher aciditiese0
- Outcome
- reduction of NO3 -e0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“greater reduction of NO3 -, and thus greater generation of internal OH- ions, occurred in plants at higher acidities”
e1“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
At higher acidity, plant tissues contained less organic anion.
- Taxon
- soybeanGlycine maxe2
- Treatment
- higher aciditiese1
- Outcome
- amounts of organic anionse0
- Direction
- smallere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“tissues contained smaller amounts of organic anions”
e1“plants at higher acidities”
e2“soybean (Glycine max [L.] Merrill) plants”
Claim · model-written summary
Root-zone acidity influenced the partitioning of internally generated hydroxide between organic-anion synthesis and efflux.
- Taxon
- soybeanGlycine maxe1
- Treatment
- Acidity of the root-zonee0
- Outcome
- partitioning of internal OH-e0
- Qualifier
- between synthesis of organic anions in the tissue and efflux to the external solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Acidity of the root-zone, therefore, influenced partitioning of internal OH- generated during NO3 - reduction between synthesis of organic anions in the tissue and efflux to the external solution in association with excess anion uptake”
e1“soybean (Glycine max [L.] Merrill) plants”
The same questions in other papers
ph · growth · Glycine max (soybean)Positive and negative results
9 papers in the same direction as this paper · 24 in the opposite direction
- negative
- negative
- negative
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See all 34 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.