Analysis Of Physiological And Metabolites Of Carex Pumila In Response To Salt Stress

Coastal vegetation is affected by a variety of stresses,salt stress is one of the most important abiotic stresses.Study on the mechanism of salt tolerance of halophytes and the regulation mechanism of salt stress environment is of great significance for coastal vegetation protection and ecological restoration,as well as salt tolerance crop breeding.In this experiment,the Carex pumila were used as the research materials to study the NaCl tolerance,which the concentration gradient is 200 mM,300 mM.400 mM,500 mM.The morphological,physiological and metabolites of the Carex pumila under salt stress were studied.The main experimental results are as follows:1?With the increase of NaCl concentration,the leaf salinity index and relative water content increased gradually.There were no obvious morphological changes of Carex pumila under 300 mM concentration.However,the leaves were yellowed and curled at 400 mM and 500 mM,and there was a phenomenon of salt secretion on the surface of leaves and stems.2?The membrane permeability of leaves was affected by salt stress,the leaf electrolyte permeability and MDA content in leaves increased with the increase of NaCl concentration,and EL and MDA content of the levels were almost flat at 400 mM and 500 mM.3?The activity of antioxidant enzymes POD,SOD,CAT and H2O2 content were increasing with the increase of salt concentration,and the active oxygen scavenging system was used to remove the reactive oxygen species.4?The leaf chlorophyll content was few affected by salt stress,but the PS II reaction center was affected by the OJIP curve,from top to bottom,followed by 200 mM,300 mM,CK,400 mM,500 mM NaCl concentration.The changes of OJIP parameters ?o??Po??Eo?DIo/RC?DIo/CSo?ETo/RC?TRo/CSo?PIABS and PIcs were not obvious at the concentration from 0 mM to 300 mM.But under the concentration of 400 mM and 500 mM,DIo/RC?DIo/CSo significantly increased,the others parameters were significantly reduced.5?The results showed that there were 39 kinds of differentially expressed metabolites,including 16 kinds of organic acids,9 kinds of amino acids,9 kinds of sugars,3 kinds of sugars,and 3 kinds of sugar alcohols,two amines.Compared with the control,the content of amino acids,sugars and sugar alcohols increased,the content of amino acids decreased and the total amino acids showed no difference.However,it was found that the amino acid content of fatty acids was decreased and the amino acids involved in the TCA cycle were increased by cluster analysis.The metabolites detected were mainly involved in glycolysis,the pentose phosphate pathway and the metabolic pathway of the three carboxylic acid(TCA)cycle.