Abstract
Abstract The physiological characterization of aluminum (Al) toxicity in C4 plants prompted this study, having maize (Zea mays cv. XL‐72.3) used as a test system. Two weeks after germination, maize plants were submitted to increasing Al concentrations (from 0 up to 81 mg L‐1) for 20 days in a growth medium with low ionic strength, after which several analyses were carried out. In root tissues, Al concentrations significantly increased between the 0 and the 81 mg L‐1 Al treatment. In the shoots nitrogen (N), phosphorus (P), and iron (Fe) significantly decreased with increasing Al concentrations, but at different rates. Magnesium (Mg) showed a tendency to decrease for Al treatments higher than 9 mg L‐1, the opposite occurring with manganese (Mn) contents. Chlorophyll a fluorescence parameters Fo and Fv/Fm showed non‐significant changes, while photosynthetic capacity, electron transport rate associated with photosystem I and cytochromes (cyt) f and b563 contents decreased above the 9 mg L‐1 Al treatment. Aluminum concentrations were correlated to phenol and quinone contents. In isolated chloroplasts, acyl lipid peroxidation increased continuously until the 81 mg L‐1 Al treatment, whereas ethylene production in intact leaves showed a sharp rise already for the 9 mg L‐1 Al treatment. Increasing Al concentrations significantly inhibited copper (Cu), zinc (Zn)‐SOD, catalase and glutathione reductase activities, whereas those of ascorbate peroxidase and dehydroascorbate reductase increased, in Al treatments with 9 mg L‐1 or higher. It was concluded that Al toxic effects in the shoot metabolism were mostly indirect, being mediated/modulated by the interactions between root Al concentrations and the concurrent inhibition of nutrients translocation mechanism(s). It was further concluded that an increasing production of chloroplastic hydroxyl radicals is coupled to the initial targets of Al mediated/modulated toxicity, being the intrachloroplastic production of H2O2, superoxide and singlet oxygen limited. It was also found, a decreased efficiency on the control of superoxide and H2O2 accumulation, since Cu,Zn‐SOD activity was ihibited and because the in vivo ascorbate peroxidase activity was limited by that of glutathione reductase. Additionally, as catalase activity was inhibited, the control of the concentration of photosynthetically‐generated H2O2 that might diffuse out of the chloroplast was also found to be less effective.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 12
Claim · model-written summary
Root aluminum concentrations increased between zero and 81 mg L‐1 treatment.
- Treatment
- 81 mg L‐1 Al treatmente0
- Outcome
- Al concentrationse0
- Direction
- increasede0
- Value
- 81 mg L‐1e0
- Comparator
- 0e0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In root tissues, Al concentrations significantly increased between the 0 and the 81 mg L‐1 Al treatment.”
t0“maize”
Claim · model-written summary
Shoot nitrogen, phosphorus and iron decreased as aluminum concentration increased.
- Organ / stage
- shootse0
- Treatment
- increasing Al concentrationse0
- Outcome
- nitrogen (N), phosphorus (P), and iron (Fe)e0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the shoots nitrogen (N), phosphorus (P), and iron (Fe) significantly decreased with increasing Al concentrations”
t0“maize”
Claim · model-written summary
Shoot magnesium tended to decrease above 9 mg L‐1 aluminum.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Magnesium (Mg) showed a tendency to decrease for Al treatments higher than 9 mg L‐1”
t0“maize”
Claim · model-written summary
Manganese showed the opposite trend to magnesium.
- Treatment
- Al treatments higher than 9 mg L‐1e1
- Outcome
- manganese (Mn) contentse0
- Qualifier
- the oppositee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the opposite occurring with manganese (Mn) contents.”
e1“Al treatments higher than 9 mg L‐1”
t0“maize”
Claim · model-written summary
Chlorophyll fluorescence parameters changed nonsignificantly.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chlorophyll a fluorescence parameters Fo and Fv/Fm showed non‐significant changes”
t0“maize”
Claim · model-written summary
Photosynthetic capacity and associated electron transport and cytochrome content decreased above 9 mg L‐1 aluminum.
- Treatment
- 9 mg L‐1 Al treatmente0
- Outcome
- photosynthetic capacity, electron transport rate associated with photosystem I and cytochromes (cyt) f and b563 contentse0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“photosynthetic capacity, electron transport rate associated with photosystem I and cytochromes (cyt) f and b563 contents decreased above the 9 mg L‐1 Al treatment”
t0“maize”
Claim · model-written summary
Aluminum concentration correlated with phenol and quinone content.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aluminum concentrations were correlated to phenol and quinone contents.”
t0“maize”
Claim · model-written summary
Chloroplast acyl lipid peroxidation increased through the highest aluminum treatment.
- Organ / stage
- isolated chloroplastse0
- Treatment
- 81 mg L‐1 Al treatmente0
- Outcome
- acyl lipid peroxidatione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In isolated chloroplasts, acyl lipid peroxidation increased continuously until the 81 mg L‐1 Al treatment”
t0“maize”
Claim · model-written summary
Leaf ethylene production rose sharply at 9 mg L‐1 aluminum.
- Organ / stage
- intact leavese0
- Treatment
- 9 mg L‐1 Al treatmente0
- Outcome
- ethylene productione0
- Direction
- sharp risee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ethylene production in intact leaves showed a sharp rise already for the 9 mg L‐1 Al treatment”
t0“maize”
Claim · model-written summary
Aluminum inhibited SOD, catalase and glutathione reductase activities.
- Treatment
- Increasing Al concentrationse0
- Outcome
- copper (Cu), zinc (Zn)‐SOD, catalase and glutathione reductase activitiese0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing Al concentrations significantly inhibited copper (Cu), zinc (Zn)‐SOD, catalase and glutathione reductase activities”
t0“maize”
Claim · model-written summary
Ascorbate peroxidase and dehydroascorbate reductase activities increased under aluminum treatment.
- Treatment
- Al treatments with 9 mg L‐1 or highere0
- Outcome
- ascorbate peroxidase and dehydroascorbate reductasee0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“those of ascorbate peroxidase and dehydroascorbate reductase increased, in Al treatments with 9 mg L‐1 or higher”
t0“maize”
Claim · model-written summary
Authors attributed shoot metabolic toxicity mainly to root aluminum and inhibited nutrient translocation.
- Outcome
- Al toxic effects in the shoot metabolisme0
- Qualifier
- interactions between root Al concentrations and the concurrent inhibition of nutrients translocation mechanism(s)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Al toxic effects in the shoot metabolism were mostly indirect, being mediated/modulated by the interactions between root Al concentrations and the concurrent inhibition of nutrients translocation mechanism(s)”
t0“maize”
The same questions in other papers
aluminium atom · nutrient: content · Zea mays (maize)Positive and negative results
14 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
18 papers more in this group
See all 22 papers →aluminium atom · physiology: antioxidant enzymes · Zea mays (maize)Results agree
3 papers in the same direction as this paper
- no effect
- negative
- negative
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.