Abstract
summary Dose‐response relationship of ozone effects on foliar nitrogen metabolism of two half‐sib families of Pinus taeda L. was studied. Trees were exposed to six ozone concentrations, ranging from 0.2 to 3 times the ambient, for two consecutive growing seasons (1988 and 1989) in open‐top chambers. Content of total chlorophyll, soluble protein and soluble amino acids, and activities of glutamine synthetase and glutamate dehydrogenase, were measured in second‐flush needles of 1989, harvested in November of 1989. Root collar diameter growth rate was also determined. Variation in depth to soil mottling, an indicator of changing redox conditions, significantly affected tree growth and nitrogen metabolism. Therefore depth to soil mottling was used as a covariate and dose‐response curves were provided with adjusted means. A decline of root collar diameter growth rate and foliar chlorophyll content was found at the highest ozone level. However, both these parameters were affected much more by soil conditions than by ozone. Glutamine synthetase, glutamate dehydrogenase and amino acids, especially glutamate and glutamine, increased by approx. 2‐fold and 3‐fold, respectively, at two and three times ambient ozone. However, soluble protein content was only affected at the highest ozone concentration, showing a 25‐fold increase. Nitrogen metabolism was more influenced by ozone than by the variation in edaphic conditions. No consistent ozone × family interaction on nitrogen metabolism could be found, but the two half‐sib families significantly differed in glutamate dehydrogenase activity and the contents of glutamate and glycine, indicating a regulatory function of this enzyme between nitrogen and carbon metabolism. The increase of amino‐N turnover and the following rise in soluble protein content are explained by the strategy of the plant to reallocate the nutrients from needles subjected to accelerated senescence by ozone. Possible implications of this process in carbohydrate metabolism and carbon partitioning are discussed.
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Claims 11
Claim · model-written summary
Depth to soil mottling significantly affected tree growth and nitrogen metabolism.
- Taxon
- Pinus taeda L.
Pinus taedat0 - Outcome
- tree growth and nitrogen metabolisme0
- Setting
- depth to soil mottlinge0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Variation in depth to soil mottling, an indicator of changing redox conditions, significantly affected tree growth and nitrogen metabolism.”
t0“Pinus taedaL.”
Claim · model-written summary
Root collar diameter growth rate declined at the highest ozone level.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- highest ozone levele0
- Outcome
- root collar diameter growth ratee0
- Direction
- declinee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A decline of root collar diameter growth rate and foliar chlorophyll content was found at the highest ozone level.”
t0“Pinus taedaL.”
Claim · model-written summary
Foliar chlorophyll content declined at the highest ozone level.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- highest ozone levele0
- Outcome
- foliar chlorophyll contente0
- Direction
- declinee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A decline of root collar diameter growth rate and foliar chlorophyll content was found at the highest ozone level.”
t0“Pinus taedaL.”
Claim · model-written summary
Soil conditions affected growth and chlorophyll more than ozone did.
- Taxon
- Pinus taeda L.Pinus taedat0
- Outcome
- both these parameterse0
- Direction
- much moree0
- Comparator
- ozonee0
- Setting
- soil conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“both these parameters were affected much more by soil conditions than by ozone”
t0“Pinus taedaL.”
Claim · model-written summary
Glutamine synthetase and glutamate dehydrogenase activities increased under elevated ozone.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- two and three times ambient ozonee0
- Gene
- Glutamine synthetase, glutamate dehydrogenasee0
- Outcome
- Glutamine synthetase, glutamate dehydrogenasee0
- Direction
- increasede0
- Value
- approx. 2‐folde0
- Comparator
- ambient ozonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Glutamine synthetase, glutamate dehydrogenase and amino acids, especially glutamate and glutamine, increased by approx. 2‐fold and 3‐fold, respectively, at two and three times ambient ozone.”
t0“Pinus taedaL.”
Claim · model-written summary
Amino acids increased approximately threefold under elevated ozone.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- two and three times ambient ozonee0
- Outcome
- amino acids, especially glutamate and glutaminee0
- Direction
- increasede0
- Value
- 3‐folde0
- Comparator
- ambient ozonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Glutamine synthetase, glutamate dehydrogenase and amino acids, especially glutamate and glutamine, increased by approx. 2‐fold and 3‐fold, respectively, at two and three times ambient ozone.”
t0“Pinus taedaL.”
Claim · model-written summary
Soluble protein content increased 25 fold only at the highest ozone concentration.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- highest ozone concentratione0
- Outcome
- soluble protein contente0
- Direction
- increasee0
- Value
- 25‐folde0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soluble protein content was only affected at the highest ozone concentration, showing a 25‐fold increase”
t0“Pinus taedaL.”
Claim · model-written summary
Ozone influenced nitrogen metabolism more than edaphic variation.
- Taxon
- Pinus taeda L.Pinus taedat0
- Treatment
- ozonee0
- Outcome
- Nitrogen metabolisme0
- Direction
- more influencede0
- Comparator
- variation in edaphic conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen metabolism was more influenced by ozone than by the variation in edaphic conditions.”
t0“Pinus taedaL.”
Claim · model-written summary
No consistent ozone by family interaction in nitrogen metabolism was found.
- Taxon
- Pinus taeda L.Pinus taedat0
- Material
- familye0
- Treatment
- ozonee0
- Outcome
- nitrogen metabolisme0
- Direction
- No consistente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No consistent ozone × family interaction on nitrogen metabolism could be found”
t0“Pinus taedaL.”
Claim · model-written summary
The half sib families differed significantly in glutamate dehydrogenase activity and glutamate and glycine contents.
- Taxon
- Pinus taeda L.Pinus taedat0
- Material
- two half‐sib familiese0
- Outcome
- glutamate dehydrogenase activity and the contents of glutamate and glycinee0
- Direction
- differede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the two half‐sib families significantly differed in glutamate dehydrogenase activity and the contents of glutamate and glycine”
t0“Pinus taedaL.”
Claim · model-written summary
The authors attribute amino nitrogen turnover and protein accumulation to nutrient reallocation from ozone senescing needles.
- Taxon
- Pinus taeda L.Pinus taedat0
- Outcome
- increase of amino‐N turnover and the following rise in soluble protein contente0
- Qualifier
- reallocate the nutrients from needles subjected to accelerated senescence by ozonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase of amino‐N turnover and the following rise in soluble protein content are explained by the strategy of the plant to reallocate the nutrients from needles subjected to accelerated senescence by ozone.”
t0“Pinus taedaL.”
The same questions in other papers
ozone · growth · Pinus taeda (loblolly pine)Results differ
13 papers in the same direction as this paper
- negative
- no effect
- no effect
10 papers more in this group
See all 14 papers →ozone · physiology: pigments · Pinus taeda (loblolly pine)Results agree
1 paper in the same direction as this paper
- negative
ozone · molecular: metabolites · Pinus taeda (loblolly pine)Results agree
2 papers in the same direction as this paper
- 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.