Abstract
Elongation of seminal and lateral roots of rice seedlings was markedly inhibited by high ammonium levels in growth medium. However, high exogenous nitrate concentrations had little inhibitory effect on root growth. The objective of this study was to elucidate the relationship between inhibition of rice root growth induced by high ammonium conditions and ammonium assimilation in the seedlings. Activity of glutamine synthetase (GS) was kept at a low level in the seminal roots of the seedlings grown under high nitrate levels. In contrast, high ammonium levels significantly enhanced the GS activity in the roots, so that Gln abundantly accumulated in the shoots. These results indicate that ammonium assimilation may be activated in the seminal roots under high ammonium conditions. Application of methionine sulfoximine (MSO), an inhibitor of GS, relieved the repression of the seminal root elongation induced by high ammonium concentrations. However, the elongation of lateral roots remained inhibited even under the same condition. Furthermore, MSO drastically increased ammonium level and remarkably decreased Gln level in the shoots grown under high ammonium conditions. These results show that, for rice seedlings, an assimilatory product of ammonium, and not ammonium itself, may serve as an endogenous indicator of the nitrogen status involved in the inhibition of seminal root elongation induced by high levels of exogenous ammonium.
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Claims 9
Claim · model-written summary
High ammonium inhibited seminal and lateral root elongation.
- Taxon
- rice seedlings
Oryza sativae0 - Organ / stage
- seminal and lateral rootse0
- Treatment
- high ammonium levelse0
- Outcome
- Elongation of seminal and lateral rootse0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Elongation of seminal and lateral roots of rice seedlings was markedly inhibited by high ammonium levels in growth medium.”
Claim · model-written summary
High nitrate had little inhibitory effect on root growth.
- Taxon
- riceOryza sativat0
- Treatment
- high exogenous nitrate concentrationse0
- Outcome
- root growthe0
- Direction
- little inhibitory effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high exogenous nitrate concentrations had little inhibitory effect on root growth.”
t0“rice”
Claim · model-written summary
GS activity remained low in seminal roots under high nitrate.
- Taxon
- riceOryza sativat0
- Organ / stage
- seminal rootse0
- Treatment
- high nitrate levelse0
- Gene
- glutamine synthetase (GS)e0
- Outcome
- Activity of glutamine synthetase (GS)e0
- Direction
- low levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Activity of glutamine synthetase (GS) was kept at a low level in the seminal roots of the seedlings grown under high nitrate levels.”
t0“rice”
Claim · model-written summary
High ammonium significantly enhanced root GS activity.
- Taxon
- riceOryza sativat0
- Organ / stage
- rootse0
- Treatment
- high ammonium levelse0
- Gene
- GSe0
- Outcome
- GS activitye0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high ammonium levels significantly enhanced the GS activity in the roots”
t0“rice”
Claim · model-written summary
Gln accumulated abundantly in shoots under high ammonium.
- Taxon
- riceOryza sativat0
- Organ / stage
- shootse0
- Outcome
- Glne0
- Direction
- abundantly accumulatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Gln abundantly accumulated in the shoots.”
t0“rice”
Claim · model-written summary
MSO relieved high-ammonium repression of seminal root elongation.
- Taxon
- riceOryza sativat0
- Treatment
- Application of methionine sulfoximine (MSO)e0
- Gene
- GSe0
- Outcome
- seminal root elongatione0
- Direction
- relievede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of methionine sulfoximine (MSO), an inhibitor of GS, relieved the repression of the seminal root elongation induced by high ammonium concentrations.”
t0“rice”
Claim · model-written summary
Lateral root elongation stayed inhibited with MSO.
- Taxon
- riceOryza sativat0
- Treatment
- MSOe0
- Outcome
- elongation of lateral rootse0
- Direction
- remained inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Application of methionine sulfoximine (MSO), an inhibitor of GS, relieved the repression of the seminal root elongation induced by high ammonium concentrations. However, the elongation of lateral roots remained inhibited even under the same condition.”
t0“rice”
Claim · model-written summary
MSO drastically raised shoot ammonium levels under high ammonium.
- Taxon
- riceOryza sativat0
- Organ / stage
- shootse0
- Treatment
- MSOe0
- Outcome
- ammonium levele0
- Direction
- drastically increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MSO drastically increased ammonium level and remarkably decreased Gln level in the shoots grown under high ammonium conditions.”
t0“rice”
Claim · model-written summary
MSO markedly lowered shoot Gln levels under high ammonium.
- Taxon
- riceOryza sativat0
- Organ / stage
- shootse0
- Treatment
- MSOe0
- Outcome
- Gln levele0
- Direction
- remarkably decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MSO drastically increased ammonium level and remarkably decreased Gln level in the shoots grown under high ammonium conditions.”
t0“rice”
The same questions in other papers
nitrogen · growth · Oryza sativa (rice)Positive and negative results
108 papers in the same direction as this paper · 402 in the opposite direction
- negative
- negative
- positive
507 papers more in this group
See all 511 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.