Abstract
The extended period of ethylene release from ethephon (2-chloroethylphosphonic acid) after application to intact tomato plants has provided a model system in which the effects of ethylene on photosynthetic metabolism and carbon partitioning has been studied. Ethylene release from leaf tissue after ethephon treatment was 10 times greater than that from untreated control leaves. The specific activity of 14C2H4 released from [14C] ethephon remained constant over several days demonstrating that the ethylene was derived from the applied ethephon. The ethephon-treated plants exhibited extreme epinasty of the leaves and 24 h after application the flower buds in the first visible cluster had abscised, leaf expansion at the apex had ceased and developing adventitious roots were visible on the lower stem. Rates of steady-state photosynthesis, respiration, photorespiration and transpiration were the same in treated and control leaves 24 h after ethephon application. Both treated and control leaves partitioned similar proportions of newly-fixed 14C from 14CO2 into neutral (46.4%), acidic (14.0%), basic (5.0%) and insoluble (34.0%) leaf fractions under steady-state conditions. The speed of 11C-assimilate movement in the stems of control plants (3.62±0.42 cm min-1 towards the apex and 4.03±0.15 cm min-1 towards the roots) was more rapid than in the ethephon-treated plants (2.90±0.31 cm min-1 upwards and 2.59±0.22 cm min-1 downwards). Furthermore, in the control plants 20.0±5.4% of the 14C exported to the plant from the source leaf was transported towards the developing flower cluster and young leaves. Twenty-four hours after ethephon application only 6.5 ±1.7% of the exported 14C was translocated towards the shoot. Contrary to some reports ethylene did not affect steady-state gas exchange processes while carbon partitioning was significantly altered indicating that ethylene effects on photosynthetic carbon metabolism are indirect and not due to direct effects on photosynthetic processes per se.
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Claims 12
Claim · model-written summary
Ethephon increased ethylene release from tomato leaves tenfold relative to untreated leaves.
- Taxon
- Tomato
Solanum lycopersicumt0 - Treatment
- ethephon treatmente0
- Outcome
- Ethylene release from leaf tissuee0
- Direction
- greatere0
- Value
- 10 timese0
- Comparator
- untreated control leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“Ethylene release from leaf tissue after ethephon treatment was 10 times greater than that from untreated control leaves”
Claim · model-written summary
The specific activity of labeled ethylene remained constant over several days, supporting its derivation from applied ethephon.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- [14C] ethephone0
- Outcome
- specific activity of 14C2H4e0
- Direction
- remained constante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“The specific activity of 14C2H4 released from [14C] ethephon remained constant over several days demonstrating that the ethylene was derived from the applied ethephon”
Claim · model-written summary
Ethephon-treated tomato plants exhibited extreme leaf epinasty.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephon-treatede0
- Outcome
- extreme epinasty of the leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“The ethephon-treated plants exhibited extreme epinasty of the leaves”
Claim · model-written summary
Flower buds in the first visible cluster abscised 24 h after ethephon application.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- flower budse0
- Treatment
- applicatione0
- Outcome
- flower buds in the first visible cluster had abscisede0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“24 h after application the flower buds in the first visible cluster had abscised”
Claim · model-written summary
Leaf expansion at the apex ceased after ethephon application.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephont1
- Outcome
- leaf expansion at the apex had ceasede0
- Direction
- ceasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
t1“ethephon (2-chloroethylphosphonic acid) after application”
e0“leaf expansion at the apex had ceased”
Claim · model-written summary
Developing adventitious roots became visible on the lower stem after ethephon application.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- adventitious rootse0
- Treatment
- ethephont1
- Outcome
- developing adventitious roots were visible on the lower steme0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
t1“ethephon (2-chloroethylphosphonic acid) after application”
e0“developing adventitious roots were visible on the lower stem”
Claim · model-written summary
Steady-state photosynthesis, respiration, photorespiration and transpiration rates were the same in treated and control tomato leaves at 24 h.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephon applicatione0
- Outcome
- Rates of steady-state photosynthesis, respiration, photorespiration and transpiratione0
- Direction
- the samee0
- Comparator
- control leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“Rates of steady-state photosynthesis, respiration, photorespiration and transpiration were the same in treated and control leaves 24 h after ethephon application”
Claim · model-written summary
Treated and control tomato leaves partitioned similar proportions of newly fixed carbon among leaf fractions.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephont1
- Outcome
- partitioned similar proportions of newly-fixed 14C from 14CO2e0
- Direction
- similare0
- Qualifier
- under steady-state conditionse0
- Comparator
- control leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“Both treated and control leaves partitioned similar proportions of newly-fixed 14C from 14CO2 into neutral (46.4%), acidic (14.0%), basic (5.0%) and insoluble (34.0%) leaf fractions under steady-state conditions”
t1“ethephon (2-chloroethylphosphonic acid) after application”
Claim · model-written summary
Ethephon slowed upward assimilate movement in tomato stems from 3.62±0.42 to 2.90±0.31 cm min-1.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephon-treated plantse0
- Outcome
- 11C-assimilate movement in the stemse0
- Direction
- more rapide0
- Value
- 2.90±0.31 cm min-1e0
- Qualifier
- 3.62±0.42 cm min-1e0
- Comparator
- control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“The speed of 11C-assimilate movement in the stems of control plants (3.62±0.42 cm min-1 towards the apex and 4.03±0.15 cm min-1 towards the roots) was more rapid than in the ethephon-treated plants (2.90±0.31 cm min-1 upwards and 2.59±0.22 cm min-1 downwards)”
Claim · model-written summary
Ethephon slowed downward assimilate movement in tomato stems from 4.03±0.15 to 2.59±0.22 cm min-1.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephon-treated plantse0
- Outcome
- 11C-assimilate movement in the stemse0
- Direction
- more rapide0
- Value
- 2.59±0.22 cm min-1e0
- Qualifier
- 4.03±0.15 cm min-1e0
- Comparator
- control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“The speed of 11C-assimilate movement in the stems of control plants (3.62±0.42 cm min-1 towards the apex and 4.03±0.15 cm min-1 towards the roots) was more rapid than in the ethephon-treated plants (2.90±0.31 cm min-1 upwards and 2.59±0.22 cm min-1 downwards)”
Claim · model-written summary
Ethephon reduced exported carbon translocated toward the tomato shoot from 20.0±5.4% to 6.5 ±1.7%.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- ethephon applicatione0
- Outcome
- exported 14C was translocated towards the shoote0
- Direction
- onlye0
- Value
- 6.5 ±1.7%e0
- Qualifier
- 20.0±5.4%e0
- Comparator
- control plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“in the control plants 20.0±5.4% of the 14C exported to the plant from the source leaf was transported towards the developing flower cluster and young leaves. Twenty-four hours after ethephon application only 6.5 ±1.7% of the exported 14C was translocated towards the shoot”
Claim · model-written summary
The authors infer that ethylene effects on tomato photosynthetic carbon metabolism are indirect.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- ethylene effects on photosynthetic carbon metabolisme0
- Qualifier
- indirect and not due to direct effects on photosynthetic processes per see0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato”
e0“ethylene effects on photosynthetic carbon metabolism are indirect and not due to direct effects on photosynthetic processes per se”
The same questions in other papers
(2-chloroethyl)phosphonic acid · growth · Solanum lycopersicum (tomato)Positive and negative results
4 papers in the same direction as this paper · 8 in the opposite direction
- positive
- positive
- positive
9 papers more in this group
See all 13 papers →(2-chloroethyl)phosphonic acid · physiology: photosynthesis · Solanum lycopersicum (tomato)Results agree
1 paper in the same direction as this paper
- 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.