The Role of Sugars in Improving Plant Abiotic Stress Tolerance

Sugars produced in plants by the process of photosynthesis play significant role in maintaining the metabolic and physiological functions of plants. Plants subjected to different abiotic stresses undergo a number of changes that may affect their growth, metabolism, photosynthesis, respiration, seed germination and many other physiological processes. Moreover, abiotic stresses are known to hinder the balance between carbon fixation and consumption through alteration in the intercellular sugar levels. The exposure of plants to high concentrations of salts leads to reduced nitrogen assimilation, growth inhibition, stomatal conductance and nutrient imbalance. Chilling or low temperature is another factor which affects plants through their membranes, reactive oxygen species production and protein denaturation. In water-deficit (drought) conditions, the rate of photosynthesis decreases due to stomatal closure. Carbohydrates are synthesized in chloroplasts by the process of photosynthesis and are transferred to cytosol in the form of triose-phosphates, where they are converted to hexose-phosphates or sucrose for transport or storage in the vacuole.