Abstract
External calcium ions (Ca2+) play a crucial role in mitigating drought stress in plants, as revealed through physiological and transcriptomic analyses using tobacco (Nicotiana tabacum L) as a model system. Under drought stress, leaves wilted, chlorophyll content decreased. The maximum photochemical efficiency of PSII (Fv/Fm) and the photosynthetic performance index decreased, fluorescence intensities at the K and L points increased, Y(NPQ) increased, net photosynthetic rate (Pn) decreased, and PSI activity (ΔI/Io) was reduced. Upon application of external calcium under drought conditions, leaf wilting was reduced, chlorophyll content increased, Fv/Fm, PIabs, and PItotal improved, fluorescence intensities at the K and L points as well as Y(NPQ) decreased, cyclic electron transport and Pn were enhanced, stomatal aperture increased, and ΔI/Io improved. Transcriptomic analysis revealed a significant reduction in the expression of genes related to the PSI and PSII reaction centers, ATP synthesis, electron transport, and antenna proteins under drought stress. The application of calcium significantly alleviated the drought-induced downregulation of these genes. In summary, Ca2+ reduces water loss in plants, increases chlorophyll content in leaves, restores PSII reaction center activity, ensures efficient photosynthetic electron transport, maintains thylakoid membrane stability, enhances cyclic electron transport, and reduces damage to the photosystem.
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Claims 14
Claim · model-written summary
Drought wilted tobacco leaves and decreased chlorophyll content.
- Taxon
- tobacco
Nicotiana tabacume0 - Treatment
- drought stresse0
- Outcome
- leaves wilted, chlorophyll content decreasede0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“using tobacco (Nicotiana tabacum L) as a model system. Under drought stress, leaves wilted, chlorophyll content decreased.”
Claim · model-written summary
Drought reduced Fv/Fm and the photosynthetic performance index.
- Taxon
- tobaccoNicotiana tabacumt0
- Treatment
- drought stresse0
- Outcome
- maximum photochemical efficiency of PSII (Fv/Fm) and the photosynthetic performance indexe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under drought stress, leaves wilted, chlorophyll content decreased. The maximum photochemical efficiency of PSII (Fv/Fm) and the photosynthetic performance index decreased”
t0“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
Drought increased K and L point fluorescence intensities and Y(NPQ).
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- drought stresse1
- Outcome
- fluorescence intensities at the K and L pointse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fluorescence intensities at the K and L points increased, Y(NPQ) increased”
e1“using tobacco (Nicotiana tabacum L) as a model system. Under drought stress”
Claim · model-written summary
Drought decreased net photosynthetic rate and PSI activity.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- drought stresse1
- Outcome
- net photosynthetic rate (Pn)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“net photosynthetic rate (Pn) decreased, and PSI activity (ΔI/Io) was reduced”
e1“using tobacco (Nicotiana tabacum L) as a model system. Under drought stress”
Claim · model-written summary
Drought reduced PSI activity.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- drought stresse1
- Outcome
- PSI activity (ΔI/Io)e0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PSI activity (ΔI/Io) was reduced”
e1“using tobacco (Nicotiana tabacum L) as a model system. Under drought stress”
Claim · model-written summary
External calcium reduced drought related leaf wilting.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- external calciume0
- Outcome
- leaf wiltinge0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Upon application of external calcium under drought conditions, leaf wilting was reduced”
e1“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium increased chlorophyll content under drought.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- chlorophyll contente0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“chlorophyll content increased”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium improved Fv/Fm, PIabs and PItotal under drought.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- Fv/Fm, PIabs, and PItotale0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fv/Fm, PIabs, and PItotal improved”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium decreased K and L point fluorescence intensities and Y(NPQ).
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- fluorescence intensities at the K and L points as well as Y(NPQ)e0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fluorescence intensities at the K and L points as well as Y(NPQ) decreased”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium enhanced cyclic electron transport and net photosynthesis under drought.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- cyclic electron transport and Pne0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cyclic electron transport and Pn were enhanced”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium increased stomatal aperture under drought.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- stomatal aperturee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“stomatal aperture increased”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
External calcium improved PSI activity under drought.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- external calciume1
- Outcome
- ΔI/Ioe0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ΔI/Io improved”
e1“Upon application of external calcium under drought conditions”
e2“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
Drought significantly reduced expression of genes for photosystem reaction centers, ATP synthesis, electron transport and antenna proteins.
- Taxon
- tobaccoNicotiana tabacume1
- Treatment
- drought stresse0
- Outcome
- expression of genes related to the PSI and PSII reaction centers, ATP synthesis, electron transport, and antenna proteinse0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a significant reduction in the expression of genes related to the PSI and PSII reaction centers, ATP synthesis, electron transport, and antenna proteins under drought stress”
e1“using tobacco (Nicotiana tabacum L) as a model system”
Claim · model-written summary
Calcium significantly alleviated drought induced downregulation of those genes.
- Taxon
- tobaccoNicotiana tabacume2
- Treatment
- application of calciume0
- Outcome
- expression of genes related to the PSI and PSII reaction centers, ATP synthesis, electron transport, and antenna proteinse1
- Direction
- alleviatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of calcium significantly alleviated the drought-induced downregulation of these genes.”
e1“a significant reduction in the expression of genes related to the PSI and PSII reaction centers, ATP synthesis, electron transport, and antenna proteins under drought stress”
e2“using tobacco (Nicotiana tabacum L) as a model system”
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