Compatible solutes, also known as compatible osmolytes, are a group of chemically diverse organic compounds that are uncharged, polar, and soluble in nature and do not interfere with the cellular metabolism even at high concentration. They mainly include proline [ 41 – 45 ], glycine betaine [ 46 , 47 ], sugar [ 48 , 49 ], and polyols [ 50 – 53 ]. Organic osmolytes are synthesised and accumulated in varying amounts amongst different plant species. For example, quaternary ammonium compound beta alanine betaine’s accumulation is restricted among few members of Plumbaginaceae [ 54 ], whereas accumulation of amino acid proline occurs in taxonomically diverse sets of plants [ 53 ]. The concentration of compatible solutes within the cell is maintained either by irreversible synthesis of the compounds or by a combination of synthesis and degradation. The biochemical pathways and genes involved in these processes have been thoroughly studied. As their accumulation is proportional to the external osmolarity, the major functions of these osmolytes are to protect the structure and to maintain osmotic balance within the cell via continuous water influx [ 24 ].