ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The role of organic solutes in the osmotic adjustment processes of the marine macroalga Enteromorpha intestinalis (L.) Link was investigated in 1986, using fresh samples collected from mid-shore rock pools at Tayport, Fife, Scotland. Natural-abundance 13C nuclear magnetic-resonance spectroscopy revealed β-dimethylsulphoniopropionate (DMSP) to be the only major low molecular weight organic osmolyte present. However, on transfer to a hypersaline medium (300% sea water; 100%=35 S‰), tissue sucrose and proline levels increased markedly, while DMSP remained constant. Recovery of optimal photosynthetic activity and increases in inorganic ion levels occurred over a similar time scale to the changes in sucrose and proline (within 48 h), indicating that these two organic solutes are involved in hyperosmotic adjustment in E. intestinalis while DMSP is not. Freshly-collected plants transferred to 300% sea water medium in the dark showed no significant increases in organic osmolytes. In contrast, starch-enrichment (16 d continuous illumination) led to enhanced synthesis of sucrose and proline in the light and in darkness, but tissue DMSP levels showed no variation throughout. These observations suggest that DMSP is not involved in short-term osmoacclimation in E. intestinalis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00393102
