Abstract
It is well known that saintpaulia leaf is damaged by the rapid temperature decrease when cold water is irrigated onto the leaf surface. We investigated this temperature sensitivity and the mechanisms of leaf damage in saintpaulia (Saintpaulia sp. cv. 'Iceberg') and other Gesneriaceae plants. Saintpaulia leaves were damaged and discolored when subjected to a rapid decrease in temperature, but not when the temperature was decreased gradually. Sensitivity to rapid temperature decrease increased within 10 to 20 min during pre-incubation at higher temperature. Injury was restricted to the palisade mesophyll cells, where there was an obvious change in the color of the chloroplasts. During a rapid temperature decrease, chlorophyll fluorescence monitored by a pulse amplitude modulated fluorometer diminished and did not recover even after rewarming to the initial temperature. Isolated chloroplasts were not directly affected by the rapid temperature decrease. Intracellular pH was monitored with a pH-dependent fluorescent dye. In palisade mesophyll cells damaged by rapid temperature decrease, the cytosolic pH decreased and the vacuolar membrane collapsed soon after a temperature decrease. In isolated chloroplasts, chlorophyll fluorescence declined when the pH of the medium was lowered. These results suggest that a rapid temperature decrease directly or indirectly affects the vacuolar membrane, resulting in a pH change in the cytosol that subsequently affects the chloroplasts in palisade mesophyll cells. We further confirmed that the same physiological damage occurs in other Gesneriaceae plants. These results strongly suggested that the vacuoles of palisade mesophyll cells collapsed during the initial phase of leaf injury.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Saintpaulia leaves were damaged and discolored by a rapid decrease in temperature but not by a gradual decrease.
- Taxon
- SaintpauliaStreptocarpus sect. Saintpauliae1
- Treatment
- rapid decrease in temperaturee1
- Outcome
- damaged and discolorede1
- Comparator
- the temperature was decreased graduallye1
Not reportedDirection
Verbatim
e1“Saintpaulia leaves were damaged and discolored when subjected to a rapid decrease in temperature, but not when the temperature was decreased gradually”
Claim · model-written summary
Sensitivity to rapid temperature decrease increased within 10 to 20 min of pre-incubation at higher temperature.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Treatment
- pre-incubation at higher temperaturee1
- Outcome
- Sensitivity to rapid temperature decreasee1
- Direction
- increasede1
- Value
- 10 to 20 mine1
Not reportedComparator
Verbatim
t0“Saintpaulia sp.”
e1“Sensitivity to rapid temperature decrease increased within 10 to 20 min during pre-incubation at higher temperature”
Claim · model-written summary
Injury from rapid temperature decrease was restricted to palisade mesophyll cells, where chloroplast color changed.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- palisade mesophyll cellse1
- Outcome
- Injury was restricted to the palisade mesophyll cellse1
Verbatim
t0“Saintpaulia sp.”
e1“Injury was restricted to the palisade mesophyll cells”
Claim · model-written summary
Chlorophyll fluorescence diminished during a rapid temperature decrease and did not recover after rewarming.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Treatment
- rapid temperature decreasee1
- Outcome
- chlorophyll fluorescencee1
- Direction
- diminishede1
Not reportedComparator
Verbatim
t0“Saintpaulia sp.”
e1“During a rapid temperature decrease, chlorophyll fluorescence monitored by a pulse amplitude modulated fluorometer diminished and did not recover even after rewarming to the initial temperature”
Claim · model-written summary
Isolated chloroplasts were not directly affected by the rapid temperature decrease.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- Isolated chloroplastse1
- Treatment
- rapid temperature decreasee1
- Outcome
- not directly affectede1
Not reportedComparatorDirection
Verbatim
t0“Saintpaulia sp.”
e1“Isolated chloroplasts were not directly affected by the rapid temperature decrease”
Claim · model-written summary
In palisade mesophyll cells damaged by rapid temperature decrease, cytosolic pH decreased.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- palisade mesophyll cellse1
- Treatment
- rapid temperature decreasee1
- Outcome
- cytosolic pHe1
- Direction
- decreasede1
Not reportedComparator
Verbatim
t0“Saintpaulia sp.”
e1“In palisade mesophyll cells damaged by rapid temperature decrease, the cytosolic pH decreased”
Claim · model-written summary
In palisade mesophyll cells damaged by rapid temperature decrease, the vacuolar membrane collapsed soon after the temperature decrease.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- palisade mesophyll cellse1
- Treatment
- rapid temperature decreasee1
- Outcome
- the vacuolar membrane collapsede1
Not reportedComparatorDirection
Verbatim
t0“Saintpaulia sp.”
e1“In palisade mesophyll cells damaged by rapid temperature decrease, the cytosolic pH decreased and the vacuolar membrane collapsed soon after a temperature decrease”
Claim · model-written summary
In isolated chloroplasts, chlorophyll fluorescence declined when the pH of the medium was lowered.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- isolated chloroplastse1
- Treatment
- the pH of the medium was lowerede1
- Outcome
- chlorophyll fluorescencee1
- Direction
- declinede1
Not reportedComparator
Verbatim
t0“Saintpaulia sp.”
e1“In isolated chloroplasts, chlorophyll fluorescence declined when the pH of the medium was lowered”
Claim · model-written summary
The same physiological damage from rapid temperature decrease occurs in other Gesneriaceae plants.
- Taxon
- Gesneriaceae plantsGesneriaceaee1
- Outcome
- the same physiological damage occurse1
Verbatim
e1“We further confirmed that the same physiological damage occurs in other Gesneriaceae plants”
Claim · model-written summary
The authors suggest that rapid temperature decrease directly or indirectly affects the vacuolar membrane, causing a cytosolic pH change that subsequently affects chloroplasts in palisade mesophyll cells.
- Taxon
- Saintpaulia sp.Streptocarpus sect. Saintpauliat0
- Organ / stage
- palisade mesophyll cellse1
- Treatment
- rapid temperature decreasee1
- Outcome
- pH change in the cytosole1
Verbatim
t0“Saintpaulia sp.”
e1“a rapid temperature decrease directly or indirectly affects the vacuolar membrane, resulting in a pH change in the cytosol that subsequently affects the chloroplasts in palisade mesophyll cells”