Study On Lipidomics Of Salicornia Europaea L. At Different Salt Concentration

In plants,salt tolerance mechanisms are very complex and involve complex processes at the molecular,cellular,metabolic,physiological and plant-wide levels.Once a plant is under salt envrionment,multiple signal transduction pathways are activated in response to salt stress.Salicornia europaea L.is one of the most salt-tolerant plants.It can withstand extreme saline environments in excess of 1 M Na Cl and shows optimal growth at moderate Na Cl concentrations(200 m M).In this experiment,plants with different salt concentrations were used to observe the physiological phenotype and analyze the qualitative and quantitative lipids.Phenotypic analysis: Salicornia showed optimal growth at 200 m M salt concentration.Salicornia plants without the participation of salt showed severe phenotypic defects,the plants grew smaller,and the stems were thin and short with slow growth and development.At high salt concentrations,Salicornia plants gradually turn yellow until withering in the later stages of growth.Analysis of physiological indicators: Salicornia europaea L.showed that it had salt-sucking ability early in its development,and scanning electron microscope observation of salt crystals could be observed on the surface.In addition,its salt glands were four-cell type,embedded between cells.Lipidomic analysis refers to the analysis of specific lipid classes by mass spectrometry.Lipidomics analysis: A total of 485 lipid components were detected in this experiment.There are 5 major lipids,including glycerides 2,sterols 3,galactosides 2,phospholipids 12,and sphingolipids 7.By means of principal component analysis,orthogonal partial least squares discriminant analysis,heat map,volcano map and other methods,statistically analyzing Salicornia plants treated with different salt concentrations,and comparing the fluidity of Salicornia and membrane lipids and differences in related double bond index and average carbon chain length.Free fatty acids(FFA),lysophosphatidylcholine(LPC),lysophosphatidylethanolamine LPE,lysophosphatidylserine(LPS),phytoceramide(Phyto-Cer),glucosylceramide(Glu Cer),phytosphingosine-1 under different salt concentrations stress –Phosphate(t-S1P),(GIPC)content of glycosyl-inositol phosphatidic acid ceramide was significantly increased.These results show that the significant changes in these contents are closely related to the salt tolerance mechanism of Salicornia europaea L..In addition,this experiment found that the increase in DBIindex is mostly phospholipids and sphingolipids,indicating that the lipid saturation is reduced,and the fluidity is higher,which may be related to the strong salt resistance of Salicornia europaea L.By comparing the average carbon chain length(ACL),it can be known that the salt chain plants have the shortest carbon chain through membrane lipids after salt treatment,and it may be sphingolipids that change the membrane fluidity.By comparing the average carbon chain length,it can be seen that the ACL coefficient of S1 P is significantly reduced at 200 m M salt concentration,so we speculate that S1 P may be related to the salt resistance of Salicornia europaea L.