| Title |
Photosynthetic efficiency, desiccation tolerance and ultrastructure in two phylogenetically distinct strains of alpine Zygnema sp. (Zygnematophyceae, Streptophyta): role of pre-akinete formation
|
|---|---|
| Published in |
Protoplasma, October 2014
|
| DOI | 10.1007/s00709-014-0703-3 |
| Pubmed ID | |
| Authors |
K. Herburger, L. A. Lewis, A. Holzinger |
| Abstract |
Two newly isolated strains of green algae from alpine regions were compared physiologically at different culture ages (1, 6, 9 and 15 months). The strains of Zygnema sp. were from different altitudes ('Saalach' (S), 440 m above sea level (a.s.l.), SAG 2419 and 'Elmau-Alm' (E-A), 1,500 m a.s.l., SAG 2418). Phylogenetic analysis of rbcL sequences grouped the strains into different major subclades of the genus. The mean diameters of the cells were 23.2 μm (Zygnema S) and 18.7 μm (Zygnema E-A) but were reduced significantly with culture age. The photophysiological response between the strains differed significantly; Zygnema S had a maximal relative electron transport rate (rETR max) of 103.4 μmol electrons m(-2) s(-1), Zygnema E-A only 61.7 μmol electrons m(-2) s(-1), and decreased significantly with culture age. Both strains showed a low-light adaption and the absence of strong photoinhibition up to 2,000 μmol photons m(-2) s(-1). Photosynthetic oxygen production showed similar results (P max Zygnema S, 527.2 μmol O2 h(-1) mg(-1) chlorophyll (chl.) a, Zygnema E-A, 390.7 μmol O2 h(-1) mg(-1) chl. a); the temperature optimum was at 35 °C for Zygnema S and 30 °C for Zygnema E-A. Increasing culture age moreover leads to the formation of pre-akinetes, which accumulate storage products as revealed by light and transmission electron microscopy. Desiccation at 84 % relative air humidity (RH) lead to a reduction of the effective quantum yield of photosystem II (PSII) (ΔFv/Fm') to zero between 90 to 120 min (Zygnema S) and between 30 to 60 min (Zygnema E-A), depending on the culture age. A partial recovery of ΔFv/Fm' was only observed in older cultures. We conclude that pre-akinetes are crucial for the aeroterrestrial lifestyle of Zygnema. |
X Demographics
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Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 55 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Chile | 1 | 2% |
| Unknown | 54 | 98% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 12 | 22% |
| Student > Bachelor | 10 | 18% |
| Student > Master | 9 | 16% |
| Student > Ph. D. Student | 6 | 11% |
| Professor > Associate Professor | 3 | 5% |
| Other | 5 | 9% |
| Unknown | 10 | 18% |
| Readers by discipline | Count | As % |
|---|---|---|
| Agricultural and Biological Sciences | 28 | 51% |
| Environmental Science | 8 | 15% |
| Biochemistry, Genetics and Molecular Biology | 3 | 5% |
| Physics and Astronomy | 1 | 2% |
| Medicine and Dentistry | 1 | 2% |
| Other | 2 | 4% |
| Unknown | 12 | 22% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 02 October 2014.
All research outputs
#15,306,972
of 22,765,347 outputs
Outputs from Protoplasma
#465
of 970 outputs
Outputs of similar age
#147,220
of 253,597 outputs
Outputs of similar age from Protoplasma
#4
of 19 outputs
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So far Altmetric has tracked 970 research outputs from this source. They receive a mean Attention Score of 2.4. This one is in the 43rd percentile – i.e., 43% of its peers scored the same or lower than it.
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