Abstract
Sugar beets (Beta vulgaris L. cv F58-554H1) were grown hydroponically in a 16-h light, 8-h dark period at a photosynthetic photon flux density of 0.5 mmol m-2 s-1 for 4 weeks in half-Hoagland culture solution containing only nitrate-nitrogen. Half of the plants were then transferred to half-Hoagland solution with ammonium-nitrogen (7.35mM), while the other half continued on 7.5 mM nitrate. Growth analysis was carried out by sampling the plants at 3-d intervals over a period of 21 d. Compared to plants supplied with nitrate, ammonium initially slowed the growth of shoots more than roots. Ammonium reduced both the area expansion of individual leaves and the relative water content of these leaves, but increased the amount of dry matter/area. The increase in specific leaf weight in ammonium-grown leaves was associated with a doubling of chloroplast volume, as much as a 62% rise in chlorophyll content, and a 4.3-fold higher accumulation of soluble protein. Ammonium nutrition substantially decreased the rate of expansion of photosynthetic (leaf) surface but did not decrease the rate of photosynthesis per area; in fact, net photosynthetic CO2 exchange rates were slightly higher than in nitrate plants, due to the build-up in stromal enzymes of the Calvin cycle, several of which increased in total extractable activity on a leaf area basis, e.g. ribulose-1,5- biphosphate carboxylase oxygenase, sedoheptulose-1,7-biphosphatase. Nitrogen source had no effect on stomatal conductance. Rates of photosynthesis per chlorophyll were decreased slightly in ammonium-grown leaves, possibly due to an increased CO2-diffusion resistance associated with the enlarged chloroplasts.
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Claims 12
Claim · model-written summary
Ammonium initially slowed shoot growth more than root growth.
- Taxon
- Sugar beets
Beta vulgaris subsp. vulgarist0 - Outcome
- growth of shootse0
- Direction
- slowede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared to plants supplied with nitrate, ammonium initially slowed the growth of shoots more than roots.”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium reduced leaf area expansion and relative water content.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- area expansion of individual leaves and the relative water contente0
- Direction
- reducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium reduced both the area expansion of individual leaves and the relative water content of these leaves”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium increased leaf dry matter per area.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- amount of dry matter/areae0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased the amount of dry matter/area”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium doubled chloroplast volume.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- chloroplast volumee0
- Direction
- doublinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“doubling of chloroplast volume”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium increased chlorophyll content up to 62%.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- chlorophyll contente0
- Direction
- risee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“as much as a 62% rise in chlorophyll content”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium raised soluble protein accumulation 4.3 fold.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- accumulation of soluble proteine0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“4.3-fold higher accumulation of soluble protein”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium decreased leaf surface expansion rate.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- rate of expansion of photosynthetic (leaf) surfacee0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium nutrition substantially decreased the rate of expansion of photosynthetic (leaf) surface”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Ammonium did not decrease photosynthesis per area.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- rate of photosynthesis per areae0
- Direction
- did not decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“did not decrease the rate of photosynthesis per area”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Net photosynthetic CO2 exchange was slightly higher under ammonium.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- net photosynthetic CO2 exchange ratese0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“net photosynthetic CO2 exchange rates were slightly higher than in nitrate plants”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Several Calvin cycle enzymes increased in extractable activity.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- total extractable activitye0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“several of which increased in total extractable activity on a leaf area basis”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Nitrogen source had no effect on stomatal conductance.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- stomatal conductancee0
- Direction
- no effecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen source had no effect on stomatal conductance”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”
Claim · model-written summary
Photosynthesis per chlorophyll decreased slightly under ammonium.
- Taxon
- Sugar beetsBeta vulgaris subsp. vulgarist0
- Outcome
- Rates of photosynthesis per chlorophylle0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rates of photosynthesis per chlorophyll were decreased slightly in ammonium-grown leaves”
t0“Sugar beets (Beta vulgaris L. cv F58-554H1)”