Effect of Exogenous Trehalose in Protection of Cells and Their Membranes in Wheat (Triticum aestivum L.) Genotypes Under Heat Stress

Trehalose (Tre) a non-reducing disaccharide, formed of two alpha D-glucose molecules, is found in many organisms and is able to protect against a variety of environmental injuries and nutritional limitations. The information regarding its occurrence and role in higher plants is scanty. In the present study, effect of trehalose (@1 mM and 1.5 mM) under heat stress of 35±2°C (moderate) and 40±2°C (severe) for 4 and 8 hours was studied in wheat (Triticum aestivum L.) genotypes viz. HD2967, PBW175, C306, PBW343, PBW621 and PBW590. Membrane thermal stability (MTS) and cell viability were significantly decreased under heat stress of eight hours. Pretreatment with Tre improved MTS and cell viability of selected wheat genotypes under stress and the effect was more pronounced with higher concentration (1.5 mM). Plant growth and vigour were negatively affected by severe heat stress (40±2°C); the reduction was compensated partially by Tre application. Dry matter accumulation and starch content of all studied wheat genotypes decreased under the heat stress, the ameliorative effect was observed with the trehalose application that helped seedlings to sustain growth under heat stress.