Growth Changes And Metabolism Analysis Of Tamarix Hispida In Response To Salt Stress

Salt damage is one of the commonly environmental stresses in plants. Salt stress affect the absorption of water, bring physiological drought in plant, and then seriously affect the growth and productivity of plant. Tamarix hispida has excellent tolerance to salt, drought and high temperature. As an ideal woody plants in study the physiological and molecular mechanisms of resistance to salt stress, the salt tolerance metabonomics research of Tamarix hispida has not been reported.The growth and morphology changes of Tamarix hispida was observed at the different time points of salt stress. After 24,72,96,120 and 168 h stress treatment of 0.25 M NaCl, the fresh weight and the relative water content, chlorophyll content, MDA content, SOD and POD activity changes of Tamarix hispida were determined. Significant changes have been found in the chlorophyll content, MDA, SOD and POD activity in Tamarix hispida. It shows that salt stress treatment has led to some changes in physiological state. So it is suitable for metabolomic analysis. In addition, the various metabolites of root and leaf samples from the different time points was extracted and then to be identified by gas phase chromatography-mass spectrometry instrument (GC-MS). After be managed, the standardized data was imported into the Simca-P software to be analyzed the differences of metabolites, then to carry out the multivariate statistical analysis.Compared with the control group, the differences of metabolites in root and leaf of each stress time point were analyzed, and 46 metabolites were identified.23,26,16,12 and 17 different metabolites were found at 24,72,96,120,168h after salt stress in leaves, respectively, and in roots the number was 9,23,25,14 and 22. The changes of metabolites in different time points were analyzed. Some metabolites such as glycerol, xylitol, inositol has appeared in every different stress time.During salt stress, the mainly different metabolites in roots and leaves of Tamarix hispida are osmotic adjustment substances such as organic acids, sugar alcohol, inositol and other soluble organic compounds. Salt stress mainly affects the metabolism of saccharides and polyols in leaves. The sugar fermentation in leaves is much more stronger than that in roots. The metabolic regulation of Tamarix hispida is tissue specific under salt stress.The multivariate statistical analysis of Tamarix hispida aboveground part total sample metabolites and root total sample metabolites was perfomed. There is a clear separation between the metabolites of Tamarix hispida under salt stress of early stage (24,72,96h) and later stage (120,168h). In different salt stress periods have different metabolic regulation. In root, metabolites were all separated by the multivariate statistical analysis. All the different stress time points of metabolic regulation were not the same. The method of multivariate statistical analysis can be used to find out the differences of metabolites quickly and effectively.