Temperature stress mediated consequences on Morphology Physiology and Secondary metabolites of Datura stramonium L

Abstract

newline xi newlineABSTRACT newlineDatura stramonium (L.), a multipurpose plant of Himalayan regions, belongs to family Solanaceae, was selected for the present study. Plant is used for the treatment of various diseases as it possesses antiseptic, sedative and anti-diarrhoeal properties. Temperature stress is emerging as key abiotic environmental factor which affect the activities and properties of plants in various ways. In the present study, to evaluate temperature stress mediated morphological, physiochemical and antioxidative defence in Datura stramonium, plants were subjected to different temperature conditions. The seedlings were exposed to six temperature conditions which include both high and low temperature i.e. 50°C, 40°C, 30°C, 25°C, 20°C and 10°C. Seedlings grown at 25°C condition were treated as control. Morphological characters analyzed were stem length, root length, total weight (fresh weight and dry weight) and leaf area. The results revealed that low and high temperature treatments significantly decreased morphological characters in comparison to plants grown in control. The analysis of physiochemical parameters involved estimation of carbohydrate and protein, and were found increased with increase as well as decrease in temperature. Non enzymatic antioxidants analyzed were alkaloids, flavonoids, ascorbic acid and tocopherol. These antioxidants were reported to be increased in all stress conditions whereas, carotenoids and chlorophyll were found increased in low temperature and decreased in high temperature treated plants. In case of enzymatic antioxidants i.e. superoxide dismutase, catalase, peroxidase, glutathione reductase, glutathione-s-transferase were examined and reported to be increased in both high and low temperature treated plants. Radical scavenging activity (DPPH) was also observed higher in stress treated plants in comparison to control. Quantitative analysis of alkaoids (Atropine, Scopolamine) was done using HPLC (High Performance Liquid Chromatography). Atropine and Scopolamine was found maximum in the plants treated with both high and low temperature (50°C and 10°C) comparison to control. The result indicated the protective mechanism of plant against oxidative damage caused by adverse growth conditions and was maintained by high content of enzymatic and non-enzymatic antioxidants. newlineKEYWORDS: Datura stramonium, Temperature stress, Antioxidants, Secondary metabolites