Inorganic and organic osmolytes accumulation in five halophytes growing in saline habitats around the Aiding Lake area in Turpan Basin, Northwest China

Halophytes dominate the plant community in saline soils. Here, osmoregulation via the accumulation of osmolytes is the basic strategy by which plants survive salinity stress. We investigated the accumulation of inorganic and organic osmolytes in the leaves of five halophytes (Tamarix hispida, Halocnemum strobilaceum, Kalidium foliatum, Karelinia caspica, and Phragmites australis) growing in the dry lakebed of Aiding Lake, Xinjiang, China. The succulent euhalophytes (H. strobilaceum and K. foliatum) accumulated large amounts of Na+, whereas other species had low Na+ concentrations. P. australis contained high concentrations of soluble carbohydrates, mainly sucrose, and amino acids, such as proline and alanine. K. caspica accumulated large quantities of mannitol. H. strobilaceum and K. foliatum had high glycine betaine contents. Only T. hispida accumulated γ-butyro betaine, which was found in high concentrations. Our findings indicate that at least four types of osmolytes (carbohydrates, polyols, amino acids, and betaines) function either alone, or in combination in the osmoregulation of these halophytes.