Abstract
Leaf elongation rate (LER) in grasses is dependent on epidermal cell supply (number) and on rate and duration of epidermal cell elongation. Nitrogen (N) fertilization increases LER. Longitudinal sections from two genotypes of tall fescue (Festuca arundinacea Schreb.), which differ by 50% in LER, were used to quantify the effects of N on the components of epidermal cell elongation and on mesophyll cell division. Rate and duration of epidermal cell elongation were determined by using a relationship between cell length and displacement velocity derived from the continuity equation. Rate of epidermal cell elongation was exponential. Relative rates of epidermal cell elongation increased by 9% with high N, even though high N increased LER by 89%. Duration of cell elongation was approximately 20 h longer in the high- than in the low-LER genotype regardless of N treatment. The percentage of mesophyll cells in division was greater in the high- than in the low-LER genotype. This increased with high N in both genotypes, indicating that LER increased with cell supply. Division of mesophyll cells adjacent to abaxial epidermal cells continued after epidermal cell division stopped, until epidermal cells had elongated to a mean length of 40 micrometers in the high-LER and a mean length of 50 micrometers in the low-LER genotype. The cell cycle length for mesophyll cells was calculated to be 12 to 13 hours. Nitrogen increased mesophyll cell number more than epidermal cell number: in both genotypes, the final number of mesophyll cells adjacent to each abaxial epidermal cell was 10 with low N and 14 with high N. A spatial model is used to describe three cell development processes relevant to leaf growth. It illustrates the overlap of mesophyll cell division and epidermal cell elongation, and the transition from epidermal cell elongation to secondary cell wall deposition.
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Claims 13
Claim · model-written summary
Epidermal cell elongation rate was exponential.
- Taxon
- tall fescue
Lolium arundinaceumt0 - Outcome
- Rate of epidermal cell elongatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rate of epidermal cell elongation was exponential”
t0“Tall Fescue”
Claim · model-written summary
High N increased relative epidermal cell elongation rates by 9%.
- Taxon
- tall fescueLolium arundinaceumt0
- Treatment
- high Ne0
- Outcome
- Relative rates of epidermal cell elongatione0
- Direction
- increasede0
- Value
- 9%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Relative rates of epidermal cell elongation increased by 9% with high N”
t0“Tall Fescue”
Claim · model-written summary
High N increased leaf elongation rate by 89%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high N increased LER by 89%”
t0“Tall Fescue”
Claim · model-written summary
Cell elongation lasted about 20 hours longer in the high-LER genotype, regardless of N.
- Taxon
- Tall FescueLolium arundinaceumt0
- Material
- high-e0
- Outcome
- Duration of cell elongatione0
- Direction
- longere0
- Value
- approximately 20 he0
- Comparator
- low-LER genotypee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Duration of cell elongation was approximately 20 h longer in the high- than in the low-LER genotype regardless of N treatment”
t0“Tall Fescue”
Claim · model-written summary
The proportion of dividing mesophyll cells was greater in the high-LER genotype.
- Taxon
- Tall FescueLolium arundinaceumt0
- Outcome
- percentage of mesophyll cells in divisione0
- Direction
- greatere0
- Comparator
- low-LER genotypee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage of mesophyll cells in division was greater in the high- than in the low-LER genotype”
t0“Tall Fescue”
Claim · model-written summary
High N increased the percentage of dividing mesophyll cells in both genotypes.
- Taxon
- Tall FescueLolium arundinaceumt0
- Treatment
- high Ne0
- Outcome
- percentage of mesophyll cells in divisione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The percentage of mesophyll cells in division was greater in the high- than in the low-LER genotype. This increased with high N in both genotypes”
t0“Tall Fescue”
Claim · model-written summary
Mesophyll cell division continued after epidermal division stopped, until epidermal cells reached 40 micrometers in high-LER plants.
- Taxon
- Tall FescueLolium arundinaceumt0
- Outcome
- Division of mesophyll cells adjacent to abaxial epidermal cells continued after epidermal cell division stoppede0
- Value
- 40 micrometerse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Division of mesophyll cells adjacent to abaxial epidermal cells continued after epidermal cell division stopped, until epidermal cells had elongated to a mean length of 40 micrometers in the high-LER”
t0“Tall Fescue”
Claim · model-written summary
The corresponding epidermal cell length was 50 micrometers in the low-LER genotype.
- Taxon
- Tall FescueLolium arundinaceumt0
- Outcome
- mean lengthe0
- Value
- 50 micrometerse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a mean length of 50 micrometers in the low-LER genotype”
t0“Tall Fescue”
Claim · model-written summary
Mesophyll cell cycle length was calculated as 12 to 13 hours.
- Taxon
- Tall FescueLolium arundinaceumt0
- Outcome
- cell cycle length for mesophyll cellse0
- Value
- 12 to 13 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The cell cycle length for mesophyll cells was calculated to be 12 to 13 hours”
t0“Tall Fescue”
Claim · model-written summary
Nitrogen increased mesophyll cell number more than epidermal cell number.
- Taxon
- Tall FescueLolium arundinaceumt0
- Treatment
- Nitrogene0
- Outcome
- mesophyll cell numbere0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen increased mesophyll cell number more than epidermal cell number”
t0“Tall Fescue”
Claim · model-written summary
Final adjacent mesophyll cell number was 10 under low N.
- Taxon
- Tall FescueLolium arundinaceumt0
- Treatment
- low Ne0
- Outcome
- final number of mesophyll cells adjacent to each abaxial epidermal celle0
- Value
- 10e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the final number of mesophyll cells adjacent to each abaxial epidermal cell was 10 with low N”
t0“Tall Fescue”
Claim · model-written summary
Final adjacent mesophyll cell number was 14 under high N.
- Taxon
- Tall FescueLolium arundinaceumt0
- Treatment
- high Ne0
- Outcome
- final number of mesophyll cells adjacent to each abaxial epidermal celle0
- Value
- 14e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the final number of mesophyll cells adjacent to each abaxial epidermal cell was 10 with low N and 14 with high N”
t0“Tall Fescue”
Claim · model-written summary
A spatial model illustrates overlap of mesophyll division and epidermal elongation and the transition to secondary wall deposition.
- Taxon
- Tall FescueLolium arundinaceumt0
- Outcome
- overlap of mesophyll cell division and epidermal cell elongatione0
- Comparator
- transition from epidermal cell elongation to secondary cell wall depositione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It illustrates the overlap of mesophyll cell division and epidermal cell elongation, and the transition from epidermal cell elongation to secondary cell wall deposition”
t0“Tall Fescue”
The same questions in other papers
nitrogen · growth · Lolium arundinaceum (tall fescue)Positive and negative results
13 papers in the same direction as this paper · 7 in the opposite direction
- positive
- negative
- negative
17 papers more in this group
See all 21 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.