Myo-inositol (MI) is a sugar-alcohol produced by most plants and animals. 1L-myo-Inositol- 1-phosphate synthase (MIPS) is the rate limiting enzyme that catalyzes the conversion of D-glucose 6- phosphate to 1L-myo-inositol-1-phosphate, the first step in the production of all inositol- containing compounds. The enzyme exists in a cytoplasmic form in a wide range of plants, animals, and fungi. In plants, a chloroplastic form of the enzyme is also widely known. The significance of MI and its direct and more downstream derivatives lies in their dual functions as signalling molecules as well as key metabolites under stress. The role of MI and its derivatives in aiding the plants to cope with various abiotic stress conditions through physiological and biochemical changes have been discussed in this paper.
Key words: abiotic stress, myo-inositol, myo-inositol-1-phosphate synthase, osmolytes, stress tolerance