Abstract
Abstract The effect of different lead (Pb) concentrations in the nutrient solution on the growth, Pb and chlorophyll a+b content, chlorophyll fluorescence and quenching parameters in the leaves of young sunflower (Helianthus annuas L.) plants was studied. The content of Pb in the analyzed plant parts increased following the increase in Pb content in the nutrient medium. This increase was expressed to a higher extent in the roots than in the stems and leaves. In the presence of high concentration of Pb in the leaf area, the dry mass and the height of plants were reduced. Lead treatment of sunflower plants led to a pronounced reduction of chlorophyll (a+b) content, accompanied by much smaller decrease of photosynthetic O evaluation rate and PSll efficiency at low light intensity. Hence, Pb effect2did not result in the destruction of the photosynthetic apparatus, but in its reduction. The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.
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Claims 10
Claim · model-written summary
Plant Pb content rose with Pb concentration in the nutrient medium.
- Taxon
- sunflower
Helianthus annuust0 - Treatment
- Pb content in the nutrient mediume0
- Outcome
- content of Pb in the analyzed plant partse0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The content of Pb in the analyzed plant parts increased following the increase in Pb content in the nutrient medium.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
Pb accumulation was greater in roots than stems and leaves.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- rootse0
- Outcome
- increasee0
- Direction
- highere0
- Comparator
- stems and leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This increase was expressed to a higher extent in the roots than in the stems and leaves.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
High leaf Pb concentration reduced plant dry mass and height.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- high concentration of Pbe0
- Outcome
- dry mass and the height of plantse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the presence of high concentration of Pb in the leaf area, the dry mass and the height of plants were reduced.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
Lead treatment markedly reduced chlorophyll content.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- Lead treatmente0
- Outcome
- chlorophyll (a+b) contente0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lead treatment of sunflower plants led to a pronounced reduction of chlorophyll (a+b) content, accompanied by much smaller decrease of photosynthetic O evaluation rate and PSll efficiency at low light intensity.”
Claim · model-written summary
Lead treatment caused smaller decreases in photosynthetic oxygen evaluation and PSII efficiency at low light.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- Lead treatmente0
- Outcome
- photosynthetic O evaluation rate and PSll efficiencye0
- Direction
- decreasee0
- Qualifier
- low light intensitye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lead treatment of sunflower plants led to a pronounced reduction of chlorophyll (a+b) content, accompanied by much smaller decrease of photosynthetic O evaluation rate and PSll efficiency at low light intensity.”
Claim · model-written summary
The authors interpret lead as reducing rather than destroying the photosynthetic apparatus.
- Taxon
- sunflowerHelianthus annuust0
- Outcome
- reductione0
- Qualifier
- photosynthetic apparatuse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Pb effect2did not result in the destruction of the photosynthetic apparatus, but in its reduction.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
The highest Pb concentration decreased photochemical quenching at saturating PFD.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- highest Pb concentratione0
- Outcome
- photochemical quenchinge0
- Direction
- decreasee0
- Qualifier
- saturating photon flux density (PFD)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
The highest Pb concentration decreased efficiency of PSll electron transport at saturating PFD.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- highest Pb concentratione0
- Outcome
- efficiency of PSll electron transporte0
- Direction
- decreasee0
- Qualifier
- saturating photon flux density (PFD)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
The highest Pb concentration significantly affected nonphotochemical fluorescence quenching.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- highest Pb concentratione0
- Outcome
- nonphotochemical fluorescence quenchinge0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.”
t0“sunflower”
t1“sunflower”
Claim · model-written summary
The authors infer increased thylakoid proton gradient and decreased photophosphorylation under highest Pb.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- highest Pb concentratione0
- Outcome
- increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest Pb concentration in the nutrient solution induced, however, at saturating photon flux density (PFD) a decrease in photochemical quenching and in the efficiency of PSll electron transport and significantly affected nonphotochemical fluorescence quenching, indicating an increase in proton gradient across the thylakoid membrane and a decrease of photophosphorylation.”
t0“sunflower”
t1“sunflower”
The same questions in other papers
lead atom · physiology: pigments · Helianthus annuus (common sunflower)Results differ
4 papers in the same direction as this paper
- negative
- negative
- negative
1 paper more in this group
See all 5 papers →lead atom · growth · Helianthus annuus (common sunflower)Results differ
10 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
10 papers more in this group
See all 14 papers →lead atom · physiology: photosynthesis · Helianthus annuus (common sunflower)Results agree
2 papers in the same direction as this paper
- negative
- 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.