Abstract
Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu in an attempt to examine the threshold toxic concentration of this metal and its effects on Mn and Fe concentration in plant tissues. Cu concentration by rice roots (Oryza sativa L.) consisted of two distinct accumulation phases: a slow phase, in solution containing up to 0.01 mg/L, and a rapid phase above this concentration. In both phases the net absorption rate, as measured by Cu concentration in the roots, increased with metal concentration in the culture solution, but the increase was much faster in the second phase. Total Cu tissue concentration showed little variation between normal tissue and that clearly showing initial symptoms of the metal toxicity. Cu toxicity, as expressed by reduced root length, appeared to be a direct result of the accumulation of excess Cu in total tissues, the average concentration being 35.1 μg/g (dw) Cu at threshold toxicity. With respect to the effects of excess Cu on Mn and Fe concentrations, it was observed that while Mn and Fe concentrations in the shoot decreased at solutions of Cu concentrations above 0.05 mg/L, in the root these metals showed different patterns, with Fe concentration decreasing above 0.05 mg/L Cu and Mn concentration showing no defined trend. It is suggested that Cu affects Mn and Fe net translocation by different mechanisms, having the X coefficient for Mn and Fe values of 0.995 and 0.581, respectively.
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Claims 9
Claim · model-written summary
At threshold Cu toxicity the average tissue Cu concentration was 35.1 μg/g (dw).
- Taxon
- rice
Oryza sativae0 - Compound
- Cue1
- Outcome
- average concentratione1
- Value
- 35.1 μg/g (dw)e1
- Qualifier
- at threshold toxicitye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e1“the average concentration being 35.1 μg/g (dw) Cu at threshold toxicity”
Claim · model-written summary
Total tissue Cu concentration showed little variation between normal tissue and tissue with initial toxicity symptoms.
- Taxon
- riceOryza sativae0
- Compound
- Cue2
- Outcome
- Total Cu tissue concentratione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e2“Total Cu tissue concentration showed little variation between normal tissue and that clearly showing initial symptoms of the metal toxicity”
Claim · model-written summary
Cu toxicity, expressed as reduced root length, appeared to be a direct result of excess Cu accumulation in total tissues.
- Taxon
- riceOryza sativae0
- Treatment
- accumulation of excess Cu in total tissuese3
- Outcome
- root lengthe3
- Direction
- reducede3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e3“Cu toxicity, as expressed by reduced root length, appeared to be a direct result of the accumulation of excess Cu in total tissues”
Claim · model-written summary
Net Cu absorption rate by rice roots increased with metal concentration in the culture solution, much faster in the second phase.
- Taxon
- riceOryza sativae0
- Treatment
- metal concentration in the culture solutione4
- Outcome
- net absorption ratee4
- Direction
- increasede4
- Qualifier
- the increase was much faster in the second phasee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e4“In both phases the net absorption rate, as measured by Cu concentration in the roots, increased with metal concentration in the culture solution, but the increase was much faster in the second phase”
Claim · model-written summary
Cu concentration by rice roots had two distinct accumulation phases, with the rapid phase above 0.01 mg/L.
- Taxon
- riceOryza sativae0
- Outcome
- two distinct accumulation phasese5
- Value
- 0.01 mg/Le5
- Qualifier
- a rapid phase above this concentratione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e5“Cu concentration by rice roots (Oryza sativa L.) consisted of two distinct accumulation phases: a slow phase, in solution containing up to 0.01 mg/L, and a rapid phase above this concentration”
Claim · model-written summary
Cu concentrations above 0.05 mg/L decreased shoot Mn and Fe concentrations in rice.
- Taxon
- riceOryza sativae0
- Treatment
- Cu concentrations above 0.05 mg/Le6
- Outcome
- Mn and Fe concentrations in the shoote6
- Direction
- decreasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e6“while Mn and Fe concentrations in the shoot decreased at solutions of Cu concentrations above 0.05 mg/L”
Claim · model-written summary
Root Fe concentration decreased above 0.05 mg/L Cu in rice.
- Taxon
- riceOryza sativae0
- Treatment
- above 0.05 mg/L Cue7
- Outcome
- Fe concentratione7
- Direction
- decreasinge7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e7“with Fe concentration decreasing above 0.05 mg/L Cu”
Claim · model-written summary
Root Mn concentration showed no defined trend with excess Cu in rice.
- Taxon
- riceOryza sativae0
- Outcome
- Mn concentratione7
- Qualifier
- no defined trende7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e7“Mn concentration showing no defined trend”
Claim · model-written summary
Cu appears to affect Mn and Fe net translocation by different mechanisms, with X coefficients of 0.995 and 0.581.
- Taxon
- riceOryza sativae0
- Treatment
- Cue7
- Outcome
- X coefficient for Mn and Fee7
- Value
- 0.995 and 0.581e7
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Long-term experiments (30 days) were carried out with rice in solution culture containing varying concentrations of Cu”
e7“It is suggested that Cu affects Mn and Fe net translocation by different mechanisms, having the X coefficient for Mn and Fe values of 0.995 and 0.581, respectively”
The same questions in other papers
copper atom · nutrient: content · Oryza sativa (rice)Positive and negative results
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See all 17 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.