Abstract
In vitro studies demonstrated that alternative oxidase (AOX) is biochemically regulated by a sulfhydryl-disulfide system, interaction with alpha-ketoacids, ubiquinone pool redox state and protein content among others. However, there is still scarce information about the in vivo regulation of the AOX. Cucumis sativus wild-type (WT) and MSC16 mutant plants were grown under two different light intensities and were used to analyze the relationship between the amount of leaf AOX protein and its in vivo capacity and activity at night and day periods. WT and MSC16 plants presented lower total respiration (V(t)), cytochrome oxidase pathway (COP) activity (v(cyt)) and alternative oxidase pathway (AOP) activity (v(alt)) when grown at low light (LL), although growth light intensity did not change the amount of cytochrome oxidase (COX) nor AOX protein. Changes of v(cyt) related to growing light conditions suggested a substrate availability and energy demand control. On the other hand, the total amount of AOX protein present in the tissue does not play a role in the regulation neither of the capacity nor of the activity of the AOP in vivo. Soluble carbohydrates were directly related to the activity of the AOP. However, although differences in soluble sugar contents mostly regulate the capacity of the AOP at different growth light intensities, additional regulatory mechanisms are necessary to fully explain the observed results.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 6
Claim · model-written summary
Low light lowered total respiration and both cytochrome and alternative oxidase pathway activity in cucumber wild type and MSC16 plants.
- Taxon
- Cucumis sativus
Cucumis sativuse1 - Material
- wild-type (WT) and MSC16 mutante1
- Treatment
- low light (LL)e0
- Outcome
- total respiration (V(t)), cytochrome oxidase pathway (COP) activity (v(cyt)) and alternative oxidase pathway (AOP) activity (v(alt))e0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“WT and MSC16 plants presented lower total respiration (V(t)), cytochrome oxidase pathway (COP) activity (v(cyt)) and alternative oxidase pathway (AOP) activity (v(alt)) when grown at low light (LL)”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”
Claim · model-written summary
Growth light intensity did not change cucumber leaf COX or AOX protein abundance.
- Taxon
- Cucumis sativusCucumis sativuse1
- Treatment
- growth light intensitye0
- Outcome
- amount of cytochrome oxidase (COX) nor AOX proteine0
- Direction
- did not changee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growth light intensity did not change the amount of cytochrome oxidase (COX) nor AOX protein”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”
Claim · model-written summary
Changes in cytochrome oxidase activity with growth light suggested control by substrate availability and energy demand.
- Taxon
- Cucumis sativusCucumis sativuse1
- Outcome
- v(cyt)e0
- Qualifier
- substrate availability and energy demand controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Changes of v(cyt) related to growing light conditions suggested a substrate availability and energy demand control”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”
Claim · model-written summary
Total AOX protein abundance did not regulate in vivo alternative oxidase pathway capacity or activity.
- Taxon
- Cucumis sativusCucumis sativuse1
- Gene
- AOX proteine0
- Outcome
- capacity nor of the activity of the AOP in vivoe0
- Direction
- does not play a rolee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the total amount of AOX protein present in the tissue does not play a role in the regulation neither of the capacity nor of the activity of the AOP in vivo”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”
Claim · model-written summary
Soluble carbohydrate content was directly related to alternative oxidase pathway activity.
- Taxon
- Cucumis sativusCucumis sativuse1
- Compound
- Soluble carbohydratese0
- Outcome
- activity of the AOPe0
- Direction
- directly relatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soluble carbohydrates were directly related to the activity of the AOP”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”
Claim · model-written summary
Soluble sugar differences mostly regulated alternative oxidase pathway capacity across growth light intensities, with other mechanisms also needed.
- Taxon
- Cucumis sativusCucumis sativuse1
- Compound
- soluble sugare0
- Outcome
- capacity of the AOPe0
- Qualifier
- additional regulatory mechanisms are necessarye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“differences in soluble sugar contents mostly regulate the capacity of the AOP at different growth light intensities, additional regulatory mechanisms are necessary to fully explain the observed results”
e1“Cucumis sativus wild-type (WT) and MSC16 mutant plants”