Understanding the tolerance of Antarctic mosses to climate change
Entry ID: ASAC_3042

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Summary
Abstract: Metadata record for data from AAS (ASAC) project 3042.

Public
Ozone depletion above Antarctica has caused large increases in springtime UVB radiation (UVBR) and recovery of the ozone layer is not expected until 2060. We have shown that increased UVBR is likely to have more negative effects on the endemic moss, Schistidium antarctici, than on two co-occurring cosmopolitan species Ceratodon purpureus and Bryum pseudotriquetrum. This is probably due to differences in their ability to screen UVBR but we need to fully characterise the UV absorbing compounds in each species, and their cellular location, to confirm this. Our team of chemists and biologists will fully characterise these potentially novel UV screens.

Project objectives:
This project brings together chemists and biologists to fully characterise the UV screens in the Antarctic endemic moss Schistidium antarctici, and two co-occurring cosmopolitan species Ceratodon purpureus and Bryum pseudotriquetrum.
Our specific aims are:
1. to extract and separate soluble and cell wall UV-B screening chemical compounds from the three moss species,
2. to identify the precise chemical structure of these compounds and their cellular location, and
3. to measure and compare the UV-B absorbing ability of the different chemical compounds.

2010-2011
New objective
4. To investigate the environmental triggers responsible for the intense red colouration observed in mosses in the 2008 season and to determine if particular chemical compounds produced by the moss are sentinels of a decline in moss populations.

Taken from the 2010-2011 Progress Report:
Progress against objectives:

1. to extract and separate soluble and cell wall UV-B screening chemical compounds from the three moss species.

The preparative separation of the cell wall UV-B screening compounds from Australian Ceratodon purpureus is well underway using semi-preparative-HPLC. Analytical HPLC analysis of individual fractions obtained show successful separation of particular compounds and we are almost at the stage of pooling equivalent fractions for identification.


2. to identify the precise chemical structure of these compounds and their cellular location, and
3. to measure and compare the UV-B absorbing ability of the different chemical compounds.

Objectives 2 and 3 will be competed once we have achieved objective 1.

4. To investigate the environmental triggers responsible for the intense red colouration observed in mosses in the 2008 season and to determine if particular chemical compounds produced by the moss are sentinels of a decline in moss populations.

Intracellular and cell wall UV absorbing compounds as well as anthocyanins have been extracted from some Ceratodon purpureus samples. Preliminary analysis of pairs of red (exposed) and green (sheltered) moss samples indicates higher concentrations of UV absorbing pigments within the cell walls of exposed mosses but no difference in the overall concentration of intracellular UV screening compounds. Surprisingly, intracellular anthocyanic pigments were twice as concentrated in the sheltered moss compared to the exposed moss.
When red, exposed moss was brought into the laboratory and grown at low light in the laboratory (21 degrees C) the colouration changed from red to green within 6 days for Bryum pseudotriquetrum and 12 days for Ceratodon purpureus. Analysis of pigments showed that over this short time, intracellular UV absorbing pigments declined in both species, but cell wall pigments and anthocyanins did not change significantly. This preliminary experiment shows that Antarctic mosses can change their pigment composition rapidly in response to changing environmental conditions and suggests that the transplant experiment will yield extremely interesting results. Longer term experiments will also show the response of cell wall pigments to a changing environment.

Related URL
Link: GET DATA
Description: Download point for the species list


Link: VIEW PROJECT HOME PAGE
Description: Public information for ASAC project 3042


Link: VIEW RELATED INFORMATION
Description: Download point for further information about the project


Link: VIEW RELATED INFORMATION
Description: Citation reference for this metadata record and dataset


Geographic Coverage
 N: -66.24 S: -66.32  E: 110.56  W: 110.48

Temporal Coverage
Start Date: 2008-09-30
Stop Date: 2013-03-31


Location Keywords
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Science Keywords
ATMOSPHERE >ATMOSPHERIC RADIATION >ULTRAVIOLET RADIATION    [Definition]
BIOLOGICAL CLASSIFICATION >PLANTS >MOSSES/HORNWORTS/LIVERWORTS    [Definition]


ISO Topic Category
BIOTA
ENVIRONMENT


Platform
FIELD SURVEYS    [Information]
FIELD INVESTIGATION    [Information]


Instrument
HPLC >High-Performance Liquid Chromatograph    [Information]


Quality
The values provided in temporal and spatial coverage are approximate only.

Taken from the 2008-2009 Progress Report:
Laboratory activity/analysis:
We have developed a methodology for efficient extraction and partitioning of the UV-B screening compounds in these mosses.

Confocal microscopy was used to examine localisation of phenolics in three Antarctic bryophyte species and also to investigate the efficiency of the various extraction techniques in removing phenolics from C. purpureus. Confocal fluorescence images showed C. purpureus had 2-fold higher amounts of cell wall-bound than intracellular phenolics whereas Bryum pseudotriquetrum contained approximately half the amount of cell wall-bound than intracellular phenolics. In the Antarctic liverwort Cephaloziella exiliflora phenolics were predominantly intracellular with little bound to the cell walls. These results indicate that B. pseudotriquetrum and C. exiliflora rely more on intracellular UV screens than C. purpureus. In addition, confocal microscopy demonstrated that the intracellular phenolics in both B. pseudotriquetrum and C. purpureus are most likely to be localised within vacuoles.

We have also ascertained that the alkali hydrolysis extraction method is successful in extracting phenolic compounds bound to cell walls of C. purpureus although we are currently trying to modify this method to avoid the use of Sodium dodecyl sulfate since this interferes with identification of the compounds.

Using subsequent chromatography techniques, aromatic compounds, unsaturated fatty acids and an unsaturated alcohol were identified as responsible for some of the high UV activity observed in the cell wall extracts. Using HPLC we have provisionally identified a number of bisflavones and some derivatives of benzoic acids as components of the UV-absorbing compounds in C. purpureus using HPLC. We have been concentrating on the cell wall fraction in this species but these compounds appear to be in both the cell wall and intracellular compartments.

Final confirmation of the exact structure of these compounds is currently underway using LC-MS and spectroscopic methods (e.g. NMR). Once we have confirmed the identity of the compounds we can assess their relative strength as UV screens and also their precise location within the cell.

Further separation of other UV-active compounds is continuing for Bryum pseudotriquetrum.

Taken from the 2009-2010 Progress Report:
Variations to work plan or objectives:
The main field work components were not possible due to the limited time at Casey and the fact that we were not there at the start or end of the summer season.

The finding that these pigments are indeed variable depending on the UV-B radiation dose is very exciting since this means that we could potentially use these mosses as proxies for historic UV radiation around the coast of Antarctica etc.

Taken from the 2010-2011 Progress Report:
Variations to work plan or objectives:
We were not able to conduct the transplant experiment in the 2010/11 season because berths were only available in late Feb for a short time. We hope to complete this experiment in 2011/12. This means that progress on Aim 4 is limited to a small pilot and comparative experiments using Australian samples. To complete the project successfully requires berths throughout the summer season to capture the moss response adequately, unfortunately this has not been possible over the past 2 seasons, but hopefully will be possible in 2011/12.

We also did not receive grant funding for this project in 2010/11 which means that progress on the other objectives was slower than we had anticipated. Despite this the project is progressing well and we have clear evidence of the ability of Antarctic mosses to respond rapidly to environmental changes.


Access Constraints
The full dataset for this project is not yet publicly available.

A copy of the species list collated during data collection is available for download from the provided URL.


Use Constraints
This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_3042 when using these data.


Keywords
UVB
ozone layer
moss
Schistidium antarctici
Ceratodon purpureus
Bryum pseudotriquetrum
climate change


Data Set Progress
IN WORK


Data Center
Australian Antarctic Data Centre, Australia    [Information]
Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: metadata at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia



Distribution
Distribution_Media: HTTP
Distribution_Size: 17 kb
Distribution_Format: Excel
Fees: Free


Personnel
SHARON ROBINSON
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Phone: +61 2 4221 5753
Fax: +61 2 4221 4135
Email: sharonr at uow.edu.au
Contact Address:
Department of Biological Sciences
University of Wollongong
Northfields Ave
City: WOLLONGONG
Province or State: New South Wales
Postal Code: 2522
Country: Australia


DAVE J. CONNELL
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


Publications/References
Waterman, M. (2008), Ultraviolet protective mechanisms in the survival of Antarctic Ceratodon purpureus and two other Antarctic bryophytes, BBiotech Honours thesis, University of Wollongong

Turnbull, J.D., Leslie, S.J., Robinson, S.A. (2009), Desiccation protects Antarctic mosses from UV-B induced DNA damage, Functional Plant Biology, 36, 214-221

Turnbull, J.D., Robinson, S.A. (2009), Accumulation of DNA damage in Antarctic mosses: correlations with ultraviolet-B radiation, temperature and turf water content vary among species., Global Change Biology, 15, 319-329

Newsham, KK., Robinson, S.A. (2009), Responses of plants in polar regions to UV-B radiation: a meta-analysis., Global Change Biology, 15, 2574-2589

Creation and Review Dates
DIF Creation Date: 2009-04-20
Last DIF Revision Date: 2014-01-10

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