Desiccation tolerance of three moss species from continental Antarctica

Citation
Sa. Robinson et al., Desiccation tolerance of three moss species from continental Antarctica, AUST J PLAN, 27(5), 2000, pp. 379-388
Citations number
50
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
AUSTRALIAN JOURNAL OF PLANT PHYSIOLOGY
ISSN journal
03107841 → ACNP
Volume
27
Issue
5
Year of publication
2000
Pages
379 - 388
Database
ISI
SICI code
0310-7841(2000)27:5<379:DTOTMS>2.0.ZU;2-D
Abstract
Tolerance of desiccation was examined in three species of moss, Grimmia ant arctici Card., Ceratodon purpureus (Hedw.) Brid. and Bryum pseudotriquetrum (Hedw.) Gaertn., Meyer et Scherb. collected from two sites of contrasting water availability in the Windmill Islands, continental Antarctica. Physiol ogical tolerance to desiccation was measured using chlorophyll fluorescence in plugs of moss during natural drying in the laboratory. Differences in r elative water content, rate of drying and the response of photosynthesis to desiccation were observed among the three species and between sites. Of th e three species studied, G. antarctici showed the lowest capacity to sustai n photosynthetic processes during desiccation, B. pseudotriquetrum had an i ntermediate response and showed the greatest plasticity and C. purpureus sh owed the greatest capacity to sustain photosynthesis during desiccation. Th ese results fit well with the known distribution of the three species with G. antarctici being limited to relatively wet sites, C. purpureus being com mon in the driest sites and B. pseudotriquetrum showing a wide distribution between these two extremes. Levels of soluble carbohydrates were also meas ured in these samples following desiccation and these indicate the presence of stachyose, an oligosaccharide known to be important in desiccation tole rance in seeds, in B. pseudotriquetrum. Both gross morphology and carbohydr ate content are likely to contribute to differences in desiccation toleranc e of the moss species. These results indicate that if the Casey region cont inues to dry out, as a result of local geological uplifting or global clima te change, we would expect to see not only reductions in the moss community but also changes in community composition. G. antarctici is likely to beco me more limited in distribution as C. purpureus and B. pseudotriquetrum exp and into drying areas.