Study On Salt Tolerant Gene Functional Verification Of Glaux Maritima And Genetic Transformation In Alfalfa

Biological enchancment of saline alkali land is a vital way to reap environment friendly land use.Conducting lookup on alfalfa salt tolerance breeding is of gorgeous value for improving saline alkali soil and its nice utilization.Currently,alfalfa salt tolerance breeding typically focuses on the excavation of salt tolerance genes,their transformation and expression in alfalfa,as well as the creation of new salt tolerant germplasm.There is still a lack of genetic transformation research on insect resistant and salt tolerant alfalfa.Glaux maritima,as an extensively allotted salt secreting halophyte in China,is an essential germplasm fabric for exploring salt tolerance genes.In this study,transcriptome sequencing technological know-how used to be used to mine salt tolerance related genes from wheatgrass,and discover its salt tolerance mechanism from its morphological shape and physiological phenotype;Through tobacco transformation,the features of applicable genes below salt stress have been verified,and salt tolerant genes had been similarly chosen for genetic transformation of Medicago sativa L.‘Caoyuan No.4’.The genetic transformation gadget was once optimized to reap transgenic plants,laying a basis for the introduction of new salt tolerant alfalfa germplasm and breeding research.The important lookup findings are as follows:1.Callus induction was once performed on 5 specific genotypes of alfalfa,amongst which Medicago sativa L.‘Caoyuan No.4’and Medicago sativa L.‘Xinjiang Daye’had a greater induction fee of over 98.89%;On the foundation of optimizing the lifestyle formula,a regeneration gadget was once installed for the cotyledon nodes of Medicago sativa L.‘Caoyuan No.4’as explants,and regenerated plant life had been fashioned after 55 days.2.The predominant salt excretion shape of Glaux maritima.is the salt gland,which is ordinarily composed of basal cells,collecting cells,and secretory cells.A After salt stress,the leaves and roots of Glaux maritima.seedlings will amplify the content material of proline to alter the osmotic stability in the plant.Both leaves and roots dispose of the collected reactive oxygen species below salt stress by using growing the pastime of enzymes such as POD and CAT,in order to decrease the damage brought about by means of salt ions.3.After salt stress,79986 genes had been assembled from the transcriptome evaluation of the leaves of Glaux maritima.Preliminary screening recognized 10089differentially expressed genes（DEGs）,which include 4375 significantly upregulated genes and 4088 significantly downregulated genes;It was once located that differential genes affecting proline synthesis,CAT activity,and GST synthesis in pathways such as“Arginine and proline metabolism”,“Peroxisome”,“MAPK signaling pathway plant”,and“Glutathione metabolism”might also be essential genes associated to salt tolerance in Glaux maritima.4.44 differentially expressed genes had been screened from the CAT and GST gene household of Glaux maritima,of which GpCAT1 and GpGSTU17 had the perfect expression.Overexpression of the GpCAT1 gene can lead to an increase in CAT activity and excessive accumulation of O₂^-content,leading to slower plant growth or death;After overexpression of the GpGSTU17 gene,the plant maintains osmotic balance by regulating the content of MDA and Pro under salt stress,and increases the body’s O₂^-content by regulating the activities of POD,CAT,APX,and GST,reducing the H₂O₂content,and improving the plant’s salt tolerance.5.A genetic transformation system was constructed for Medicago sativa L.‘Caoyuan No.4’（using cotyledon nodes as explants,OD600≈0.4-0.6 Agrobacterium strain GV3101+150μM/L As,cocultured for 3 days）,obtained transgenic positive plants（4%）;Further overexpression of GpCAT1 and GpGSTU17 genes in Medicago sativa L.‘Caoyuan No.4’and resulted in transgenic positive plants（3%）,laying the foundation for the cultivation of salt tolerant Medicago sativa L.‘Caoyuan No.4’.