Abstract
Abstract At 23°C, both C 2 H 4 and CO 2 stimulated the germination of freshly imbibed upper cocklebur ( Xanthium pennsylvanicum Wallr.) seeds, but C 2 H 4 , unlike CO 2 , changed to an inhibitor of germination under some soaking conditions. However, when seeds were pre‐soaked for more than several hours at 23 °C prior to treatment, C 2 H 4 strongly inhibited their germination at 33 °C, the degree of inhibition increasing with the duration of pre‐soaking. Maximum inhibition occurred at 1–3 cm 3 m −3 C 2 H 4 when seeds were pre‐soaked for 1 week; further increases of C 2 H 4 concentration and pre‐soaking period decreased the inhibitory effect. C 2 H 4 was synergistic with CO 2 when C 2 H 4 promoted germination, whereas it was antagonistic when inhibitory. Such a transition of the C 2 H 4 action occurred at ca. 27 °C. Also 1‐andnocyclopropane‐1‐carboxylic acid, a C 2 H 4 precursor, inhibited the germination of pre‐soaked seeds at 33 °C, although it promoted the germination at 23 °C. When pre‐soaked seeds were prepared for germination by chilling at 8 °C for 3 d, the inhibitory effect of C 2 H 4 on the subsequent germination was manifested even at 23 °C. The reversal of the C 2 H 4 action from promotion to inhibition in cocklebur seed germination is discussed in relation to the engagement of two respiratory pathways in the imbibed seeds.
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Claims 13
Claim · model-written summary
At 23°C ethylene stimulated freshly imbibed cocklebur seed germination.
- Taxon
- cocklebur ( Xanthium pennsylvanicum Wallr.)
Xanthium strumariume0 - Treatment
- C 2 H 4e0
- Outcome
- germinatione0
- Direction
- stimulatede0
- Qualifier
- At 23°Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 23°C, both C 2 H 4 and CO 2 stimulated the germination of freshly imbibed upper cocklebur ( Xanthium pennsylvanicum Wallr.) seeds”
Claim · model-written summary
At 23°C carbon dioxide stimulated freshly imbibed cocklebur seed germination.
- Taxon
- cocklebur ( Xanthium pennsylvanicum Wallr.)Xanthium strumariume0
- Treatment
- CO 2e0
- Outcome
- germinatione0
- Direction
- stimulatede0
- Qualifier
- At 23°Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At 23°C, both C 2 H 4 and CO 2 stimulated the germination of freshly imbibed upper cocklebur ( Xanthium pennsylvanicum Wallr.) seeds”
Claim · model-written summary
After several hours presoak at 23°C, ethylene inhibited germination at 33°C.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- C 2 H 4e0
- Outcome
- germinatione0
- Direction
- inhibitede0
- Qualifier
- pre‐soaked for more than several hours at 23 °Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“when seeds were pre‐soaked for more than several hours at 23 °C prior to treatment, C 2 H 4 strongly inhibited their germination at 33 °C”
t0“cocklebur”
Claim · model-written summary
Ethylene inhibition increased with presoak duration.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- duration of pre‐soakinge0
- Outcome
- degree of inhibitione0
- Direction
- increasinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the degree of inhibition increasing with the duration of pre‐soaking”
t0“cocklebur”
Claim · model-written summary
Ethylene inhibition was maximal at 1–3 cm3 m−3 after one week presoak.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- C 2 H 4e0
- Outcome
- Maximum inhibitione0
- Value
- 1–3 cm 3 m −3e0
- Qualifier
- pre‐soaked for 1 weeke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maximum inhibition occurred at 1–3 cm 3 m −3 C 2 H 4 when seeds were pre‐soaked for 1 week”
t0“cocklebur”
Claim · model-written summary
Further ethylene concentration increases diminished inhibition.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- C 2 H 4 concentratione0
- Outcome
- inhibitory effecte0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“further increases of C 2 H 4 concentration and pre‐soaking period decreased the inhibitory effect”
t0“cocklebur”
Claim · model-written summary
Further presoak duration diminished inhibition.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- pre‐soaking periode0
- Outcome
- inhibitory effecte0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“further increases of C 2 H 4 concentration and pre‐soaking period decreased the inhibitory effect”
t0“cocklebur”
Claim · model-written summary
Ethylene and carbon dioxide acted synergistically when ethylene promoted germination.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- C 2 H 4e0
- Outcome
- synergistic with CO 2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“C 2 H 4 was synergistic with CO 2 when C 2 H 4 promoted germination”
t0“cocklebur”
Claim · model-written summary
Ethylene and carbon dioxide acted antagonistically when ethylene inhibited germination.
- Taxon
- cockleburXanthium strumariumt0
- Outcome
- antagonistic when inhibitorye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it was antagonistic when inhibitory”
t0“cocklebur”
Claim · model-written summary
Ethylene action switched near 27°C.
- Taxon
- cockleburXanthium strumariumt0
- Outcome
- transition of the C 2 H 4 actione0
- Value
- ca. 27 °Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Such a transition of the C 2 H 4 action occurred at ca. 27 °C”
t0“cocklebur”
Claim · model-written summary
The ethylene precursor inhibited presoak seed germination at 33°C.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- 1‐andnocyclopropane‐1‐carboxylic acide0
- Outcome
- germination of pre‐soaked seedse0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“1‐andnocyclopropane‐1‐carboxylic acid, a C 2 H 4 precursor, inhibited the germination of pre‐soaked seeds at 33 °C”
t0“cocklebur”
Claim · model-written summary
The ethylene precursor promoted germination at 23°C.
- Taxon
- cockleburXanthium strumariumt0
- Outcome
- germinatione0
- Direction
- promotede0
- Qualifier
- 23 °Ce0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“although it promoted the germination at 23 °C”
t0“cocklebur”
Claim · model-written summary
Chilling allowed ethylene inhibition of germination even at 23°C.
- Taxon
- cockleburXanthium strumariumt0
- Treatment
- chilling at 8 °C for 3 de0
- Outcome
- subsequent germinatione0
- Direction
- inhibitorye0
- Qualifier
- even at 23 °Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When pre‐soaked seeds were prepared for germination by chilling at 8 °C for 3 d, the inhibitory effect of C 2 H 4 on the subsequent germination was manifested even at 23 °C”
t0“cocklebur”
The same questions in other papers
cold · growth · Xanthium strumarium (cocklebur)Positive and negative results
2 in the opposite direction
- positive
- positive
co2 · growth · Xanthium strumarium (cocklebur)Positive and negative results
11 papers in the same direction as this paper · 4 in the opposite direction
- negative
- positive
- positive
12 papers more in this group
See all 16 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.