Cyclic environmental factors only partially explain the seasonal variability of photoprotection and physiology in two mosses from an unforested headwater stream
Nunez-Olivera, E; Otero, S; Tomas, R; Fabon, G; Martinez-Abaigar, J
| HERO ID | 644272 |
|---|---|
| In Press | No |
| Year | 2010 |
| Title | Cyclic environmental factors only partially explain the seasonal variability of photoprotection and physiology in two mosses from an unforested headwater stream |
| Authors | Nunez-Olivera, E; Otero, S; Tomas, R; Fabon, G; Martinez-Abaigar, J |
| Journal | Bryologist |
| Volume | 113 |
| Issue | 2 |
| Page Numbers | 277-291 |
| Abstract | We studied the relationships between environmental variables and the physiology of two (semi-)aquatic mosses (Bryum pseudotriquetrum and Fontinalis antipyretica) in an unforested headwater stream over a three year period. Neither environmental or physiological variables showed significant interannual variations. Most environmental variables (water temperature, stratospheric ozone, and photosynthetic, UV-A and UV-B radiation) showed distinct seasonal variations, but only a few physiological ones did. In both species, photoprotection variables (the activity of the xanthophyll cycle and the bulk UV absorbance of the methanol-extractable UV-absorbing compounds, MEUVAC) varied more seasonally than variables related to physiological activity, such as the sclerophylly index and chlorophyll fluorescence parameters (F-v/F-m and Phi(PSII)). Changes in physiological activity would be attenuated by the buffering capacity of water with respect to the influence of environmental factors, and dynamic variables like F-v/F-m and Phi(PSII) would be little determined by cyclic environmental factors. In B. pseudotriquetrum, both MEUVAC and kaempferol 3,7-O-diglycoside (a potentially UV-protective flavonoid) were positively associated with radiation levels, whereas in F. antipyretica photoprotection mechanisms were not correlated with any environmental variable. In addition, MEUVAC was 3-4 fold higher in B. pseudotriquetrum than in F. antipyretica. Thus, different photoprotection mechanisms, with a different environmental regulation, can be suggested for these two species. DNA damage was not found in any sample, probably because both species displayed efficient DNA repair mechanisms. |
| Doi | 10.1639/0007-2745-113.2.277 |
| Url | http://www.bioone.org/doi/abs/10.1639/0007-2745-113.2.277 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science 000279869600008 |
| Is Public | Yes |
| Keyword | Aquatic bryophytes; kaempferol derivatives; mountain streams; seasonal; changes; ultraviolet radiation; uv-b radiation; exsertifolia subsp cordifolia; stratospheric ozone; depletion; uncinata hedw. loeske; aquatic bryophytes; ultraviolet-radiation; absorbing compounds; dna-damage; phenolic-compounds; antarctic mosses |
| Is Qa | No |
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