Ferimazova, Naila and Felcmanova, Kristina and Setlikova, Eva and Kuepper, Hendrik and Maldener, Iris and Hauska, Guenther and Sediva, Barbora and Prasil, Ondrej (2013) Regulation of photosynthesis during heterocyst differentiation in Anabaena sp strain PCC 7120 investigated in vivo at single-cell level by chlorophyll fluorescence kinetic microscopy. PHOTOSYNTHESIS RESEARCH, 116 (1). pp. 79-91. ISSN 0166-8595,
Full text not available from this repository. (Request a copy)Abstract
Changes of photosynthetic activity in vivo of individual heterocysts and vegetative cells in the diazotrophic cyanobacterium Anabaena sp. strain PCC 7120 during the course of diazotrophic acclimation were determined using fluorescence kinetic microscopy (FKM). Distinct phases of stress and acclimation following nitrogen step-down were observed. The first was a period of perception, in which the cells used their internally stored nitrogen without detectable loss of PS II activity or pigments. In the second, the stress phase of nitrogen limitation, the cell differentiation occurred and an abrupt decline of fluorescence yield was observed. This decline in fluorescence was not paralleled by a corresponding decline in photosynthetic pigment content and PS II activity. Both maximal quantum yield and sustained electron flow were not altered in vegetative cells, only in the forming heterocysts. The third, acclimation phase started first in the differentiating heterocysts with a recovery of PS II photochemical yields Afterwards, the onset of nitrogenase activity was observed, followed by the restoration of antenna pigments in the vegetative cells, but not in the heterocysts. Surprisingly, mature heterocysts were found to have an intact PS II as judged by photochemical yields, but a strongly reduced PS II-associated antenna as judged by decreased F (0). The possible importance of the functional PS II in heterocysts is discussed. Also, the FKM approach allowed to follow in vivo and evaluate the heterogeneity in photosynthetic performance among individual vegetative cells as well as heterocysts in the course of diazotrophic acclimation. Some cells along the filament (so-called "superbright cells") were observed to display transiently increased fluorescence yield, which apparently proceeded by apoptosis.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | BLUE-GREEN-ALGAE; MARINE CYANOBACTERIUM TRICHODESMIUM; DEPENDENT OXYGEN-CONSUMPTION; NITROGENASE ACTIVITY; ELECTRON-TRANSPORT; FILAMENTOUS CYANOBACTERIA; FIXATION; CYLINDRICA; PCC-7120; STRESS; Acclimation to abiotic stress; Heterocyst differentiation; Nitrogen fixation; Two-dimensional (imaging) measurements of chlorophyll fluorescence kinetics of individual |
| Subjects: | 500 Science > 580 Botanical sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Pflanzenwissenschaften > Alumni or Retired > Prof. Dr. Günter Hauska |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Apr 2020 08:30 |
| Last Modified: | 02 Apr 2020 08:30 |
| URI: | https://pred.uni-regensburg.de/id/eprint/16153 |
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