“…Compatible solutes.-As described in previous sections, compatible solutes contribute to the well-known tolerance mechanism called osmotic adjustment. These metabolites ("osmolytes" or "osmo-protectants") are monosaccharides (fructose and glucose), di-and oligo-saccharides (sucrose, trehalose, raffinose and fructan), sugar alcohols or polyols (mannitol, inositol, methylated inositol, glycerol and pinitol), amino acids (proline,citrulline, pipecolic acid), betaines (glycine betaine, alanine betaine, proline betaine, hydroxyproline betaine), tertiary amines (ectoine; 1,4,5,6-tetrahydro-2-methyl-4-carboxylpyrimidine) and sulphonium compounds (choline o-sulfate, dimethyl sulfoniumpropironate-DMSP) (Robinson & Jones 1986, Pareek et al 2010, Slama et al 2015. Nevertheless, enhanced accumulation of mentioned osmolytes has been reported in various plants exposed to abiotic stresses, but threshold level and diversity of the osmolytes depend on the species and environmental condition (Szabados et al 2011).…”