ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Photosynthetic assimilation of 14CO2 by the symbiotic green alga Platymonas convolutae Parke et Manton in the marine flatworm Convoluta roscoffensis Graff has been investigated and compared with that in free-living P. subcordiformis and P. tetrathele. All Platymonas species investigated rapidly incorporate 14CO2 into a complex variety of soluble and insoluble assimilates. The rate of dark fixation is considerably lower in P. convolutae. Typical 14C-assimilate patterns are rather uniform in all Platymonas species, but the time courses of 14C-labelling of several compounds are very different. The percentage of 14C-aspartate and 14C-malate is significantly higher in P. convolutae after short-term-photosynthesis, whereas 14C-labelled phosphate esters predominate in the free-living Platymonas species. A comparison of the kinetics of 14C-labelling and of the distribution of 14C-activity between soluble and insoluble fractions suggests that glucose and fructose, not mannitol, as well as several amino acids (especially alanine) move from the algal partner to the tissue of the animal host. The significance of these findings is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00387150
