Abstract
Chlorophyll fluorescence imaging was used to measure stomatal closure in response to desiccation of Tradescantia virginiana leaves grown under high (90%) and moderate (55%) relative humidities (RHs), or transferred between these humidities. Stomata in leaves grown at high RH were less responsive to desiccation than those of leaves grown at moderate RH. Stomata of plants transferred from moderate RH conditions to high RH showed the same diminished closure in response to desiccation as did stomata that developed at high RH. This response was found both when the leaves were fully expanded and when still actively expanding during the moderate RH pre-treatment. Four days of exposure to high RH was the minimal exposure time to induce the diminished closure response. When leaves were grown in high RH prior to a 10 d moderate RH treatment, the reduced stomatal closure response to desiccation was only reversed in leaves (regions) which were actively expanding during moderate RH treatment. This indicates that with respect to stomatal responses to desiccation, high RH leaf regions have a limited capacity to adapt to moderate RH conditions. The decrease in responsiveness to desiccation of the stomata, induced by long-term exposure to high RH, was not due to osmotic adjustment in the leaves. Within 1 d after transferring moderate RH-grown plants to a high RH, the abscisic acid (ABA) concentration of their leaves decreased to the low level of ABA found in high RH-grown leaves. The closure response in leaves exposed to high RH for 5 d, however, could not be fully restored by the application of ABA. Transferring plants from high to moderate RH resulted in increased ABA levels within 2 d without a recovery of the stomatal closing response. It is discussed that the diminished stomatal closure in plants exposed to high RH could be due to changes in the signalling pathway for ABA-related closure of stomata or to an increased sequestration of ABA by mesophyll tissue or the symplast in the epidermis, induced by a longer period (several days) of a low ABA level.
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Claims 10
Claim · model-written summary
High-humidity leaves closed stomata less in response to desiccation.
- Taxon
- Tradescantia virginiana
Tradescantia virginianat0 - Treatment
- high RHe0
- Outcome
- responsive to desiccatione0
- Direction
- lesse0
- Comparator
- moderate RHe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stomata in leaves grown at high RH were less responsive to desiccation than those of leaves grown at moderate RH.”
t0“Tradescantia virginiana”
Claim · model-written summary
Transfer from moderate to high RH caused diminished stomatal closure.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- transferred from moderate RH conditions to high RHe0
- Outcome
- closure in response to desiccatione0
- Direction
- diminishede0
- Comparator
- stomata that developed at high RHe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Stomata of plants transferred from moderate RH conditions to high RH showed the same diminished closure in response to desiccation as did stomata that developed at high RH.”
t0“Tradescantia virginiana”
Claim · model-written summary
Diminished closure occurred in fully expanded and expanding leaves.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Organ / stage
- leavese0
- Outcome
- diminished closure in response to desiccatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This response was found both when the leaves were fully expanded and when still actively expanding during the moderate RH pre-treatment.”
e1“diminished closure in response to desiccation”
t0“Tradescantia virginiana”
Claim · model-written summary
Four days of high RH was the minimum to induce diminished closure.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Outcome
- diminished closure responsee0
- Value
- Four dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Four days of exposure to high RH was the minimal exposure time to induce the diminished closure response.”
t0“Tradescantia virginiana”
Claim · model-written summary
Moderate humidity reversed reduced closure only in expanding leaf regions.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- moderate RH treatmente1
- Outcome
- reduced stomatal closure response to desiccatione0
- Direction
- reversede0
- Qualifier
- actively expandinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the reduced stomatal closure response to desiccation was only reversed in leaves (regions) which were actively expanding during moderate RH treatment”
e1“10 d moderate RH treatment”
t0“Tradescantia virginiana”
Claim · model-written summary
The reduced closure was not due to leaf osmotic adjustment.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Outcome
- decrease in responsiveness to desiccation of the stomatae0
- Qualifier
- not due to osmotic adjustment in the leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decrease in responsiveness to desiccation of the stomata, induced by long-term exposure to high RH, was not due to osmotic adjustment in the leaves.”
t0“Tradescantia virginiana”
Claim · model-written summary
Leaf ABA decreased within one day after transfer to high RH.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- transferring moderate RH-grown plants to a high RHe0
- Outcome
- abscisic acid (ABA) concentration of their leavese0
- Direction
- decreasede0
- Value
- 1 de0
- Comparator
- high RH-grown leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Within 1 d after transferring moderate RH-grown plants to a high RH, the abscisic acid (ABA) concentration of their leaves decreased to the low level of ABA found in high RH-grown leaves.”
t0“Tradescantia virginiana”
Claim · model-written summary
ABA application did not fully restore closure after five days of high RH.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- application of ABAe0
- Outcome
- closure responsee0
- Direction
- could not be fully restorede0
- Qualifier
- high RH for 5 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The closure response in leaves exposed to high RH for 5 d, however, could not be fully restored by the application of ABA.”
t0“Tradescantia virginiana”
Claim · model-written summary
Transfer to moderate RH increased ABA within two days.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- Transferring plants from high to moderate RHe0
- Outcome
- ABA levelse0
- Direction
- increasede0
- Value
- 2 de0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transferring plants from high to moderate RH resulted in increased ABA levels within 2 d without a recovery of the stomatal closing response.”
t0“Tradescantia virginiana”
Claim · model-written summary
Transfer to moderate RH did not recover stomatal closure.
- Taxon
- Tradescantia virginianaTradescantia virginianat0
- Treatment
- Transferring plants from high to moderate RHe0
- Outcome
- stomatal closing responsee0
- Direction
- without a recoverye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transferring plants from high to moderate RH resulted in increased ABA levels within 2 d without a recovery of the stomatal closing response.”
t0“Tradescantia virginiana”
The same questions in other papers
humidity · physiology: gas exchange · Tradescantia virginiana (Virginia spiderwort)Positive and negative results
2 in the opposite direction
- 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.