Abstract
Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3). Growth with urea is restricted by 18.8 mm NO(3) (-), 50 mm methylammonia, 10 mm citrate or 100 mum hydroxyurea, substances which are much less restrictive or nonrestrictive in the presence of ammonia nitrogen source. The restrictive conditions of urea assimilation were examined as possible bases for selection schemes to recover urease-overproducing mutants. Since urease has higher methionine levels than the soybean seed proteins among which it is found, such selections may be a model for improving seed protein quality by plant cell culture techniques.Callus will not grow with 1 mm urea plus 18.8 mm KNO(3). Urease levels decrease 80% within two divisions after transfer from MS nitrogen source to 1 mm urea plus 18.8 mm KNO(3). Hydroxyurea is a potent inhibitor of soybean urease and this appears to be the basis for its inhibition of urea utilization by callus cells.Stationary phase suspension cultures grown with MS nitrogen source exhibit trace or zero urease levels. Soon after transfer to fresh medium (24 hours after escape from lag), urease levels increase in the presence of both MS or urea nitrogen source. However, the increase is 10 to 20 times greater in the presence of urea. NH(4)Cl (50 mm) lowers urease induction by 50% whereas 50 mm methylammonium chloride results in more drastic reductions in urea-stimulated urease levels. Citrate (10 mm) completely blocks urease synthesis in the presence of urea.Ammonia and methylammonia do not inhibit soybean urease nor do they appreciably inhibit urea uptake by suspension cultures. It appears likely that methylammonia inhibits urea utilization in cultured soybean cells primarily due to its "repressive" effect on urease synthesis.Citrate does not inhibit urease activity in vitro and exhibits only a partial inhibition (0-50% in several experiments) of urea uptake. It appears likely that the citrate elimination of urease production by cultured soybean cells is due to its chelation of trace Ni(2+) in the growth medium. Dixon et al. (J. Am. Chem. Soc. 97: 4131-4133, 1975) have reported that jack bean (Canavalia ensiformis) urease contains nickel at the active site.
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Claims 16
Claim · model-written summary
Soybean cells grew more slowly with 25 mm urea as sole nitrogen source than with the MS nitrogen source
- Taxon
- Glycine max
Glycine maxe1 - Material
- Kanrich varietye1
- Treatment
- 25 mm urea as the sole nitrogen sourcee1
- Outcome
- cells growe1
- Direction
- slowere1
- Comparator
- nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Growth with urea was restricted by 18.8 mm nitrate, 50 mm methylammonia, 10 mm citrate or 100 µM hydroxyurea
- Taxon
- Glycine maxGlycine maxe1
- Treatment
- 18.8 mm NO(3) (-), 50 mm methylammonia, 10 mm citrate or 100 mum hydroxyureae2
- Outcome
- Growth with ureae2
- Direction
- restrictede2
- Comparator
- ammonia nitrogen sourcee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
e2“Growth with urea is restricted by 18.8 mm NO(3) (-), 50 mm methylammonia, 10 mm citrate or 100 mum hydroxyurea, substances which are much less restrictive or nonrestrictive in the presence of ammonia nitrogen source”
Claim · model-written summary
Callus did not grow with 1 mm urea plus 18.8 mm KNO3
Not reportedComparatorDirection
Verbatim
e1“Callus will not grow with 1 mm urea plus 18.8 mm KNO(3)”
Claim · model-written summary
Urease levels decreased 80% within two divisions after transfer from MS to 1 mm urea plus 18.8 mm KNO3
- Taxon
- Glycine maxGlycine maxe2
- Treatment
- transfer from MS nitrogen source to 1 mm urea plus 18.8 mm KNO(3)e1
- Outcome
- Urease levelse1
- Direction
- decreasee1
- Value
- 80%e1
- Comparator
- MS nitrogen sourcee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Urease levels decrease 80% within two divisions after transfer from MS nitrogen source to 1 mm urea plus 18.8 mm KNO(3)”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Hydroxyurea is a potent inhibitor of soybean urease, which appears to be the basis for its inhibition of urea utilization by callus cells
- Taxon
- soybeanGlycine maxe1
- Compound
- Hydroxyureae1
- Outcome
- inhibition of urea utilization by callus cellse1
- Qualifier
- Hydroxyurea is a potent inhibitor of soybean ureasee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Hydroxyurea is a potent inhibitor of soybean urease and this appears to be the basis for its inhibition of urea utilization by callus cells”
Claim · model-written summary
Urease levels increased in the presence of urea and MS nitrogen source, by 10 to 20 times more with urea
- Taxon
- soybeanGlycine maxe3
- Treatment
- ureae1
- Outcome
- urease levelse1
- Direction
- increasee1
- Value
- 10 to 20 timese2
- Comparator
- MSe1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“urease levels increase in the presence of both MS or urea nitrogen source”
e2“However, the increase is 10 to 20 times greater in the presence of urea”
e3“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
NH(4)Cl (50 mm) lowered urease induction by 50%
- Taxon
- soybeanGlycine maxe2
- Treatment
- NH(4)Cl (50 mm)e1
- Outcome
- urease inductione1
- Direction
- lowerse1
- Value
- 50%e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“NH(4)Cl (50 mm) lowers urease induction by 50% whereas 50 mm methylammonium chloride results in more drastic reductions in urea-stimulated urease levels”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
50 mm methylammonium chloride produced more drastic reductions in urea-stimulated urease levels than NH4Cl
- Taxon
- soybeanGlycine maxe2
- Treatment
- 50 mm methylammonium chloridee1
- Outcome
- urea-stimulated urease levelse1
- Direction
- reductionse1
- Qualifier
- more drastice1
- Comparator
- NH(4)Cl (50 mm)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“NH(4)Cl (50 mm) lowers urease induction by 50% whereas 50 mm methylammonium chloride results in more drastic reductions in urea-stimulated urease levels”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Citrate (10 mm) completely blocked urease synthesis in the presence of urea
- Taxon
- soybeanGlycine maxe2
- Treatment
- Citrate (10 mm)e1
- Outcome
- urease synthesise1
- Direction
- blockse1
- Qualifier
- in the presence of ureae1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Citrate (10 mm) completely blocks urease synthesis in the presence of urea”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Ammonia and methylammonia did not inhibit soybean urease
- Taxon
- soybeanGlycine maxe1
- Treatment
- Ammonia and methylammoniae1
- Outcome
- soybean ureasee1
- Direction
- do not inhibite1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Ammonia and methylammonia do not inhibit soybean urease nor do they appreciably inhibit urea uptake by suspension cultures”
Claim · model-written summary
Ammonia and methylammonia did not appreciably inhibit urea uptake by suspension cultures
- Taxon
- soybeanGlycine maxe1
- Treatment
- Ammonia and methylammoniae1
- Outcome
- urea uptake by suspension culturese1
- Direction
- nor do they appreciably inhibite1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Ammonia and methylammonia do not inhibit soybean urease nor do they appreciably inhibit urea uptake by suspension cultures”
Claim · model-written summary
Methylammonia inhibits urea utilization in cultured soybean cells, likely through its repressive effect on urease synthesis
- Taxon
- soybeanGlycine maxe1
- Compound
- methylammoniae1
- Outcome
- urea utilizatione1
- Qualifier
- repressivee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“It appears likely that methylammonia inhibits urea utilization in cultured soybean cells primarily due to its "repressive" effect on urease synthesis”
Claim · model-written summary
Citrate did not inhibit urease activity in vitro
- Taxon
- soybeanGlycine maxe2
- Treatment
- Citratee1
- Outcome
- urease activity in vitroe1
- Direction
- does not inhibite1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Citrate does not inhibit urease activity in vitro and exhibits only a partial inhibition (0-50% in several experiments) of urea uptake”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Citrate exhibited only a partial inhibition of urea uptake, 0-50% in several experiments
- Taxon
- soybeanGlycine maxe2
- Treatment
- Citratee1
- Outcome
- urea uptakee1
- Direction
- partial inhibitione1
- Value
- 0-50%e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Citrate does not inhibit urease activity in vitro and exhibits only a partial inhibition (0-50% in several experiments) of urea uptake”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
Claim · model-written summary
Citrate eliminated urease production in cultured soybean cells, likely through chelation of trace Ni(2+) in the growth medium
- Taxon
- soybeanGlycine maxe1
- Compound
- Ni(2+)e1
- Outcome
- citrate elimination of urease productione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“It appears likely that the citrate elimination of urease production by cultured soybean cells is due to its chelation of trace Ni(2+) in the growth medium”
Claim · model-written summary
Urea-based selection schemes may be a model for improving seed protein quality by plant cell culture techniques
- Taxon
- soybeanGlycine maxe2
- Outcome
- improving seed protein qualitye1
- Qualifier
- by plant cell culture techniquese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Such selections may be a model for improving seed protein quality by plant cell culture techniques”
e2“Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3)”
The same questions in other papers
nitrogen · growth · Glycine max (soybean)Positive and negative results
35 papers in the same direction as this paper · 117 in the opposite direction
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