Abstract
A study was made of the effect of atmospheric CO 2 enrichment and increased nitrogen availability on primary leaf senescence in sunflower (Helianthus annuus L.). First, markers normally used for monitoring leaf development (dry weight, leaf surface area, protein content, photosynthetic pigment levels, CO 2 fixation rate, changes in the enzymes involved in nitrogen metabolism, and plant-tissue oxidative status) were measured in plants grown for 42 days under ambient (400 µL L −1 ) or enriched CO 2 conditions (800 µL L −1 ), and with two different levels of nitrate supply (10 mM and 25 mM). Second, two-dimensional electrophoresis (2-DE) was used to compare primary-leaf protein profiles (16 and 42 days) in sunflowers grown under ambient or enriched CO 2 conditions with elevated nitrate supply. Plants grown under enriched CO 2 conditions and with high nitrogen supply displayed faster growth, a higher CO 2 fixation rate, and increased activity by antioxidative and nitrogen-metabolism-related enzymes than those grown under elevated CO 2 with low nitrogen supply. These findings indicate that CO 2 enrichment and increased nitrate availability slow down the induction of senescence, suggesting that senescence may be directly related to leaf C/N ratio. These results enhance our understanding of the sunflower’s response to increased atmospheric CO 2 levels, one of the environmental factors favoring climate change.
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Claims 5
Claim · model-written summary
Sunflower grown under enriched CO2 and high nitrogen supply grew faster than under elevated CO2 with low nitrogen supply.
- Taxon
- sunflower
Helianthus annuust0 - Treatment
- enriched CO 2 conditions and with high nitrogen supplye4
- Outcome
- growthe4
- Direction
- fastere4
- Comparator
- elevated CO 2 with low nitrogen supplye4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Plants grown under enriched CO 2 conditions and with high nitrogen supply displayed faster growth, a higher CO 2 fixation rate, and increased activity by antioxidative and nitrogen-metabolism-related enzymes than those grown under elevated CO 2 with low nitrogen supply”
t0“sunflower (Helianthus annuus L.)”
Claim · model-written summary
Sunflower grown under enriched CO2 and high nitrogen supply had a higher CO2 fixation rate than under elevated CO2 with low nitrogen supply.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- enriched CO 2 conditions and with high nitrogen supplye4
- Outcome
- CO 2 fixation ratee4
- Direction
- highere4
- Comparator
- elevated CO 2 with low nitrogen supplye4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Plants grown under enriched CO 2 conditions and with high nitrogen supply displayed faster growth, a higher CO 2 fixation rate, and increased activity by antioxidative and nitrogen-metabolism-related enzymes than those grown under elevated CO 2 with low nitrogen supply”
t0“sunflower (Helianthus annuus L.)”
Claim · model-written summary
Sunflower grown under enriched CO2 and high nitrogen supply had increased activity of antioxidative and nitrogen-metabolism-related enzymes than under elevated CO2 with low nitrogen supply.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- enriched CO 2 conditions and with high nitrogen supplye4
- Outcome
- activity by antioxidative and nitrogen-metabolism-related enzymese4
- Direction
- increasede4
- Comparator
- elevated CO 2 with low nitrogen supplye4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Plants grown under enriched CO 2 conditions and with high nitrogen supply displayed faster growth, a higher CO 2 fixation rate, and increased activity by antioxidative and nitrogen-metabolism-related enzymes than those grown under elevated CO 2 with low nitrogen supply”
t0“sunflower (Helianthus annuus L.)”
Claim · model-written summary
CO2 enrichment and increased nitrate availability slow down the induction of leaf senescence in sunflower.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- CO 2 enrichment and increased nitrate availabilitye5
- Outcome
- induction of senescencee5
- Direction
- slow downe5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“These findings indicate that CO 2 enrichment and increased nitrate availability slow down the induction of senescence”
t0“sunflower (Helianthus annuus L.)”
Claim · model-written summary
Senescence may be directly related to the leaf C/N ratio in sunflower.
- Taxon
- sunflowerHelianthus annuust0
- Organ / stage
- leafe6
- Outcome
- senescencee6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“senescence may be directly related to leaf C/N ratio”
t0“sunflower (Helianthus annuus L.)”
The same questions in other papers
nitrogen · growth · Helianthus annuus (common sunflower)Results differ
62 papers in the same direction as this paper · 12 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- negative
- negative
72 papers more in this group
See all 76 papers →co2 · physiology: enzyme activity · Helianthus annuus (common sunflower)Positive and negative results
2 in the opposite direction
- negative
- no effect
co2 · growth · Helianthus annuus (common sunflower)Positive and negative results
2 papers in the same direction as this paper · 5 in the opposite direction
- no effect
- no effect
- no effect
4 papers more in this group
See all 8 papers →nitrogen · physiology: enzyme activity · Helianthus annuus (common sunflower)Results agree
1 paper in the same direction as this paper
- positive
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.