Abstract
Accumulation of compatible solutes or osmolytes is a general response of plants to abiotic stress conditions, but we still have very limited knowledge on the relevance of this response for stress tolerance mechanisms of a given tolerant species. We have determined the levels of common osmolytes (proline, glycine betaine and total soluble sugars) in three Juncus species, two salt tolerant (J. acutus and J. maritimus) and one salt-sensitive (J. articulatus), subjected to salt or water stress treatments. Correlation of the patterns of osmolyte accumulation with salt tolerance of the three taxa, indicated that biosynthesis of Pro (but not the increase of glycine betaine or sugar contents) plays a relevant role in the stress tolerance of the analysed Juncus species
