Abstract
Sunflower seeds were planted under field conditions in order to investigate the behavioral pattern of photooxidation tolerance in plants in response to leaf aging. During pollination stage, the leaves were theoretically divided into three sections including young, middle aged and senescent leaves, so that the cell defense potential would change with leaf aging, and then modeling of different intensities of light and its effects on light oxidation of biological materials in the leaves of different ages was investigated. The results from the first series of experiments showed that despite of no change of chlorophyll content in leaves due to leaf aging, total protein content and membrane stability index were declined. Furthermore, lipid peroxidation and hydrogen peroxide were increased in respond to leaf aging. Meanwhile, the activity of hydrogen peroxide scavenging enzymes and glutathione S-transferase in senescent leaves were higher than that of young leaves. Overall, the results showed that with any increase in leaf age, defense potential of cells slowed down and the production of oxidants exceeded the scavenging potential of the cells. The results of modeling of different intensities of light revealed that in senescent leaves under high light intensities, hydrogen peroxide reached to its highest levels. However, under those light condition, hydrogen peroxide scavenging enzymes and glutathione S-transferse activities were recorded at amounts lower than that of low light intensities. The outcome of the above mentioned factors lead to oxidation of chlorophyll and subsequently its content reduction under highlight intensities in aged leaves. In total, under high light intensities, the damage of oxidation stress on aged leaves was more intensified compared to young leaves mainly due to diminished defense potential of stress faced cells.
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Claims 11
Claim · model-written summary
Leaf aging did not change sunflower leaf chlorophyll content.
- Taxon
- sunflower
Helianthus annuust0 - Organ / stage
- leavese0
- Outcome
- chlorophyll contente0
- Direction
- no changee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“no change of chlorophyll content in leaves due to leaf aging”
t0“sunflower”
Claim · model-written summary
Sunflower leaf aging decreased total protein content and membrane stability index.
- Taxon
- sunflowerHelianthus annuust0
- Outcome
- total protein content and membrane stability indexe0
- Direction
- declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total protein content and membrane stability index were declined”
t0“sunflower”
Claim · model-written summary
Sunflower leaf aging increased lipid peroxidation and hydrogen peroxide.
- Taxon
- sunflowerHelianthus annuust0
- Outcome
- lipid peroxidation and hydrogen peroxidee0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lipid peroxidation and hydrogen peroxide were increased in respond to leaf aging”
t0“sunflower”
Claim · model-written summary
Senescent sunflower leaves had higher hydrogen peroxide scavenging enzyme activity than young leaves.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- senescent leavese0
- Outcome
- activity of hydrogen peroxide scavenging enzymese0
- Direction
- highere0
- Comparator
- young leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the activity of hydrogen peroxide scavenging enzymes and glutathione S-transferase in senescent leaves were higher than that of young leaves”
t0“sunflower”
Claim · model-written summary
Senescent sunflower leaves had higher glutathione S-transferase activity than young leaves.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- senescent leavese0
- Outcome
- glutathione S-transferasee0
- Direction
- highere0
- Comparator
- young leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the activity of hydrogen peroxide scavenging enzymes and glutathione S-transferase in senescent leaves were higher than that of young leaves”
t0“sunflower”
Claim · model-written summary
Sunflower cellular defense potential declined with increasing leaf age while oxidant production exceeded scavenging.
- Taxon
- sunflowerHelianthus annuust0
- Outcome
- defense potential of cellse0
- Direction
- slowed downe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with any increase in leaf age, defense potential of cells slowed down and the production of oxidants exceeded the scavenging potential of the cells”
t0“sunflower”
Claim · model-written summary
Hydrogen peroxide in senescent sunflower leaves reached its highest level under high light intensity.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- senescent leavese0
- Treatment
- high light intensitiese0
- Outcome
- hydrogen peroxidee0
- Direction
- higheste0
- Comparator
- low light intensitiese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in senescent leaves under high light intensities, hydrogen peroxide reached to its highest levels”
e1“low light intensities”
t0“sunflower”
Claim · model-written summary
Under high light intensity, hydrogen peroxide scavenging enzyme activity was lower than under low light intensity in aged sunflower leaves.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- high light intensitiese1
- Outcome
- hydrogen peroxide scavenging enzymese0
- Direction
- lowere0
- Comparator
- low light intensitiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under those light condition, hydrogen peroxide scavenging enzymes and glutathione S-transferse activities were recorded at amounts lower than that of low light intensities”
e1“under high light intensities, the damage of oxidation stress”
t0“sunflower”
Claim · model-written summary
Under high light intensity, glutathione S-transferase activity was lower than under low light intensity in aged sunflower leaves.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- high light intensitiese1
- Outcome
- glutathione S-transferse activitiese0
- Direction
- lowere0
- Comparator
- low light intensitiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under those light condition, hydrogen peroxide scavenging enzymes and glutathione S-transferse activities were recorded at amounts lower than that of low light intensities”
e1“under high light intensities, the damage of oxidation stress”
t0“sunflower”
Claim · model-written summary
High light caused chlorophyll oxidation and reduced its content in aged sunflower leaves.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- aged leavese0
- Treatment
- highlight intensitiese0
- Outcome
- chlorophylle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lead to oxidation of chlorophyll and subsequently its content reduction under highlight intensities in aged leaves”
t0“sunflower”
Claim · model-written summary
Under high light, oxidative damage was greater in aged sunflower leaves than young leaves.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- aged leavese0
- Treatment
- high light intensitiese0
- Outcome
- damage of oxidation stresse0
- Direction
- more intensifiede0
- Comparator
- young leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“under high light intensities, the damage of oxidation stress on aged leaves was more intensified compared to young leaves”
t0“sunflower”
The same questions in other papers
light · physiology: oxidative · Helianthus annuus (common sunflower)Positive and negative results
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- positive
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light · molecular: metabolites · Helianthus annuus (common sunflower)Positive and negative results
7 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- positive
7 papers more in this group
See all 11 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.