Abstract
• The combined effects of the two pollutants, cadmium and ozone, on sunflower (Helianthus annuus) metabolism are analysed here. • Photosysnthetic processes and ascorbate metabolism were studied in sunflower plants grown for 15 d in the presence of cadmium and exposed to acute O3 treatments. • CO2 assimilation rate was reduced in plants subjected to Cd(II) and/or O3 treatments, but no alterations in stomatal conductance and Fv : Fm ratio were observed. Rubisco activity was significantly reduced only in plants grown in the presence of cadmium indicating that the photosynthetic process is mainly altered by this factor. Photochemical quenching and the quantum efficiency of PSII in steady-state conditions were significantly depressed and nonphotochemical quenching increased in stressed plants. Cd(II) and O3 also strongly affected ascorbate metabolism. • The changes in ascorbate redox state and the increase in ascorbate-redox enzymes strongly supported an ascorbate over-utilization in Cd(II) and/or O3–treated plants. However, the increase in ascorbate-based detoxification mechanisms did not provide complete protection against the oxidative stress imposed by the two pollutants, since an increase in lipid peroxidation and protein oxidation accompanied a decrease in photosynthesis under pollutant exposure.
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 10
Claim · model-written summary
Cd and/or O3 treatment reduced CO2 assimilation rate in sunflower.
- Taxon
- sunflower (Helianthus annuus)
Helianthus annuuse0 - Treatment
- Cd(II) and/or O3e1
- Outcome
- CO2 assimilation ratee1
- Direction
- reducede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e1“CO2 assimilation rate was reduced in plants subjected to Cd(II) and/or O3 treatments, but no alterations in stomatal conductance and Fv : Fm ratio were observed”
Claim · model-written summary
Cd and/or O3 treatment caused no alterations in stomatal conductance and Fv : Fm ratio in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and/or O3e1
- Outcome
- stomatal conductance and Fv : Fm ratioe1
- Direction
- no alterationse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e1“CO2 assimilation rate was reduced in plants subjected to Cd(II) and/or O3 treatments, but no alterations in stomatal conductance and Fv : Fm ratio were observed”
Claim · model-written summary
Rubisco activity was significantly reduced in sunflower grown in the presence of cadmium.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- the presence of cadmiume2
- Outcome
- Rubisco activitye2
- Direction
- reducede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e2“Rubisco activity was significantly reduced only in plants grown in the presence of cadmium indicating that the photosynthetic process is mainly altered by this factor”
Claim · model-written summary
Cd and/or O3 significantly depressed photochemical quenching and the quantum efficiency of PSII in steady-state conditions in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and/or O3e1
- Outcome
- Photochemical quenching and the quantum efficiency of PSIIe3
- Direction
- depressede3
- Qualifier
- in steady-state conditionse3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e1“CO2 assimilation rate was reduced in plants subjected to Cd(II) and/or O3 treatments, but no alterations in stomatal conductance and Fv : Fm ratio were observed”
e3“Photochemical quenching and the quantum efficiency of PSII in steady-state conditions were significantly depressed and nonphotochemical quenching increased in stressed plants”
Claim · model-written summary
Cd and/or O3 increased nonphotochemical quenching in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and/or O3e1
- Outcome
- nonphotochemical quenchinge3
- Direction
- increasede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e1“CO2 assimilation rate was reduced in plants subjected to Cd(II) and/or O3 treatments, but no alterations in stomatal conductance and Fv : Fm ratio were observed”
e3“Photochemical quenching and the quantum efficiency of PSII in steady-state conditions were significantly depressed and nonphotochemical quenching increased in stressed plants”
Claim · model-written summary
Changes in ascorbate redox state and increased ascorbate-redox enzymes indicate ascorbate over-utilization in Cd and/or O3-treated sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and/or O3–treated plantse4
- Compound
- ascorbatee4
- Outcome
- ascorbate over-utilizatione4
- Qualifier
- The changes in ascorbate redox state and the increase in ascorbate-redox enzymese4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e4“The changes in ascorbate redox state and the increase in ascorbate-redox enzymes strongly supported an ascorbate over-utilization in Cd(II) and/or O3–treated plants”
Claim · model-written summary
Cd and/or O3 increased ascorbate-redox enzymes in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and/or O3–treated plantse4
- Outcome
- ascorbate-redox enzymese4
- Direction
- increasee4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e4“The changes in ascorbate redox state and the increase in ascorbate-redox enzymes strongly supported an ascorbate over-utilization in Cd(II) and/or O3–treated plants”
Claim · model-written summary
Cd and O3 strongly affected ascorbate metabolism in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- Cd(II) and O3e5
- Outcome
- ascorbate metabolisme5
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e5“Cd(II) and O3 also strongly affected ascorbate metabolism”
Claim · model-written summary
Lipid peroxidation and protein oxidation increased under pollutant exposure in sunflower, accompanying decreased photosynthesis.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- pollutant exposuree6
- Outcome
- lipid peroxidation and protein oxidatione6
- Direction
- increasee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e6“the increase in ascorbate-based detoxification mechanisms did not provide complete protection against the oxidative stress imposed by the two pollutants, since an increase in lipid peroxidation and protein oxidation accompanied a decrease in photosynthesis under pollutant exposure”
Claim · model-written summary
Increased ascorbate-based detoxification did not give complete protection against the oxidative stress of the two pollutants in sunflower.
- Taxon
- sunflower (Helianthus annuus)Helianthus annuuse0
- Treatment
- the two pollutantse6
- Outcome
- complete protection against the oxidative stresse6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“on sunflower (Helianthus annuus) metabolism are analysed here”
e6“the increase in ascorbate-based detoxification mechanisms did not provide complete protection against the oxidative stress imposed by the two pollutants, since an increase in lipid peroxidation and protein oxidation accompanied a decrease in photosynthesis under pollutant exposure”
The same questions in other papers
cadmium atom · physiology: gas exchange · Helianthus annuus (common sunflower)Results differ
2 papers in the same direction as this paper
- no effect
- negative
cadmium atom · physiology: photosynthesis · Helianthus annuus (common sunflower)Results agree
8 papers in the same direction as this paper
- negative
- no effect
- negative
5 papers more in this group
See all 9 papers →ozone · physiology: photosynthesis · Helianthus annuus (common sunflower)Results agree
2 papers in the same direction as this paper
- no effect
- no effect
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.