Effect of Heat Stress on Fatty Acids Profiles of Aloe vera and Bryophyllum pinnatum Leaves

Plants are exposed to various environmental stresses which lead to a number of physiological and biochemical changes. One of the most usual forms of environmental stress encountered by plants is heat stress. The present study was therefore conducted to investigate the effects of heat stress on the fatty acids profiles of Aloe vera and Bryophyllum pinnatum leaves. Fourteen plants of each species were investigated in the present study. The plants were then divided into two groups, each group comprising of seven plants. One group from each species was kept under control environmental conditions with daily temperature of 28 ± 2°C while the other set was kept in green house where average daily temperature ranged between 38°C and 43°C. After 15 days leaves were collected from both groups of plants. Lipids were extracted from the leaves. The fatty acids were analyzed by Gas Chromatography Mass spectrometry. Results exhibited that Palmitic acid was found to be the most abundant fatty acid in the leaves of both set of plants; the second most abundant fatty acids were linoleic acid and linolenic acid, while lauric acid was present in the lowest concentrations. Significant changes were observed in the concentration of fatty acids in response to heat stress. The concentration of saturated fatty acids like palmitic acid and stearic acid increased while unsaturated fatty acids like linoleic acid and linolenic acid become decreased in response to heat stress. In both plant species total saturated fatty acids increased while total unsaturated fatty acids became decreased significantly with heat stress.