Abstract
Abstract The effects of Al on nitrate uptake and on the activity of the nitrate reductase (NR) in two hybrid cultivars of sorghum (Sorghum bicolor (L.) Moench) differing in Al tolerance were studied. The nitrate uptake by intact root system was strongly reduced by Al in both cultivars, but mainly in the Al‐sensitive cultivar. The kinetic constants also changed in the presence of Al: Vmax decreased 98% and 71% and Km increased 267% and 42% in the Al‐sensitive and Al‐tolerant cultivar, respectively. Aluminum reduced the in vitro NR activity on the roots and shoots of both cultivars, especially of the Al‐sensitive cultivar. Aluminum added to the nutrient solution or to the reaction mixture, however, inhibited differentially the NR of the roots and shoots, indicating marked differences between the enzymes from these two tissues. Aluminum reduced the Vmax but did not affect the Km of nitrate activation of the shoot NR. Therefore, Al inhibition of the NR was non‐competitive and could not be reversed by increasing nitrate concentration. Aluminum not only reduced the nitrate uptake but also had a direct effect on the NR and consequently on nitrate reduction. A correlation between NR tolerance to Al and plant tolerance to Al was observed.
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Claims 12
Claim · model-written summary
Al reduced nitrate uptake in both cultivars, particularly the sensitive one.
- Material
- Al‐sensitive cultivare0
- Organ / stage
- root systeme0
- Treatment
- Ale0
- Outcome
- nitrate uptakee0
- Direction
- reducede0
SorghumNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The nitrate uptake by intact root system was strongly reduced by Al in both cultivars, but mainly in the Al‐sensitive cultivar”
t0“sorghum”
Claim · model-written summary
Al decreased Vmax by 98% in the sensitive cultivar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Vmax decreased 98% and 71% and Km increased 267% and 42% in the Al‐sensitive and Al‐tolerant cultivar, respectively”
t0“sorghum”
Claim · model-written summary
Al decreased Vmax by 71% in the tolerant cultivar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Vmax decreased 98% and 71% and Km increased 267% and 42% in the Al‐sensitive and Al‐tolerant cultivar, respectively”
t0“sorghum”
Claim · model-written summary
Al increased Km by 267% in the sensitive cultivar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Vmax decreased 98% and 71% and Km increased 267% and 42% in the Al‐sensitive and Al‐tolerant cultivar, respectively”
t0“sorghum”
Claim · model-written summary
Al increased Km by 42% in the tolerant cultivar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Vmax decreased 98% and 71% and Km increased 267% and 42% in the Al‐sensitive and Al‐tolerant cultivar, respectively”
t0“sorghum”
Claim · model-written summary
Al reduced root and shoot NR activity, especially in the sensitive cultivar.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum reduced the in vitro NR activity on the roots and shoots of both cultivars, especially of the Al‐sensitive cultivar”
t0“sorghum”
Claim · model-written summary
Al applied in nutrient solution and reaction mixture inhibited root and shoot NR differently.
- Treatment
- Aluminume0
- Gene
- NRe0
- Outcome
- NR of the roots and shootse0
- Direction
- inhibited differentiallye0
- Comparator
- nutrient solution or to the reaction mixturee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum added to the nutrient solution or to the reaction mixture, however, inhibited differentially the NR of the roots and shoots”
t0“sorghum”
Claim · model-written summary
Al reduced shoot NR Vmax.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum reduced the Vmax but did not affect the Km of nitrate activation of the shoot NR”
t0“sorghum”
Claim · model-written summary
Al did not affect shoot NR Km.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum reduced the Vmax but did not affect the Km of nitrate activation of the shoot NR”
t0“sorghum”
Claim · model-written summary
Authors interpret Al inhibition of NR as noncompetitive and irreversible by extra nitrate.
- Gene
- NRe0
- Outcome
- Al inhibition of the NRe0
- Qualifier
- non‐competitive and could not be reversed by increasing nitrate concentratione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Al inhibition of the NR was non‐competitive and could not be reversed by increasing nitrate concentration”
t0“sorghum”
Claim · model-written summary
Al had a direct effect on NR and nitrate reduction.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum not only reduced the nitrate uptake but also had a direct effect on the NR and consequently on nitrate reduction”
t0“sorghum”
Claim · model-written summary
NR tolerance to Al correlated with plant tolerance to Al.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A correlation between NR tolerance to Al and plant tolerance to Al was observed”
t0“sorghum”
The same questions in other papers
aluminium atom · nutrient: content · SorghumPositive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- negative
1 paper more in this group
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.