CO2 fixation and chlorophyll a fluorescence in leaves of Ramonda serbica during a dehydration-rehydration cycle
Changes in CO(2) photo-assimilation and PSII photochemical efficiency in Ramonda serbica leaves during a dehydration-rehydration cycle were examined. The rate of CO(2) photo-assimilation was greatly reduced during dehydration, but recovery was complete with rehydration when the relative water conten...
| Veröffentlicht in: | Journal of plant physiology. - 1979. - 165(2008), 7 vom: 05. Mai, Seite 723-33 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Journal of plant physiology |
| Schlagworte: | Journal Article Electrolytes Pigments, Biological Water 059QF0KO0R Chlorophyll 1406-65-1 Carbon Dioxide 142M471B3J Phosphoenolpyruvate Carboxylase mehr... |
| Zusammenfassung: | Changes in CO(2) photo-assimilation and PSII photochemical efficiency in Ramonda serbica leaves during a dehydration-rehydration cycle were examined. The rate of CO(2) photo-assimilation was greatly reduced during dehydration, but recovery was complete with rehydration when the relative water content of leaves reached values similar to those of well-hydrated, control leaves. The results showed that the response of R. serbica leaves to severe water stress involves two different mechanisms. In the first, CO(2) assimilation is limited by stomata closure that creates an excess proton concentration in the lumen and activates non-photochemical quenching. This plays an important role in the mechanism of photoprotection by dissipation of excitation energy. When dehydration became severe and leaf RWC reached very low values, the electron transport rate (ETR) decreased markedly, while the capacity for regulatory mechanisms such as q(NP) (non-photochemical quenching) was greatly reduced. For severely dehydrated leaves of R. serbica, it appears that reactive oxygen species (ROS) formation is better prevented by mechanisms that quench chlorophyll triplet formation via lutein |
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| Beschreibung: | Date Completed 22.04.2009 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1618-1328 |