Analysis Of Salt Tolerance Function Of PagERF114 Gene In Populus Alba×P.grandulos

Saline-alkali land is one of the main environmental stresses that harm plant growth and reduce biomass accumulation in the world,which will cause great losses to the economic and ecological benefits of forest stands.Therefore,it is of great significance to cultivate new varieties with higher salt tolerance.AP2/ERF transcription factors are always involved in physiological activities in plants and play an important role in responding to biotic and abiotic stresses.In this study,84K poplar（Populus alba×P.grandulos）was used as the material.From the transcriptome data sequencing results after salt stress,We are selected PagERF114,a transcription factor gene with high expression ratio induced by salt stress.Firstly,PagERF114was cloned and vector-constructed.secondly,genetic transformation was carried out.Finally,the salt stress resistance of the PagERF114-OE and WT were compared.The main research results are shown.（1）The PagERF114 gene with a total length of 720 bp was cloned,containing 240 amino acids.The AP2 domain is contained at the 53-116 amino acid sequence,which has typical AP2family gene domain characteristics,indicating that PagERF114 gene belongs to ERF subfamily.Through multiple sequence alignment and phylogenetic trees,it was found that PagERF114gene had certain homology with AT1G43160 in Arabidopsis thaliana,and the closest relative was Populus trichocarpa KAI5569617.1.（2）qRT-PCR results showed that salt stress treatment could induce the expression of PagERF114 gene.The expression level of genes in leaf and root tissues was relatively stable,and the trend from 0 to 24 h increased,reaching the highest peak at 24 h and decreasing at 48 h.Comparing 24 h with 0 h,the expression in leaves and roots increased by 7.4 and 6.1 times,respectively.This expression pattern also illustrates sensitivity to stress responses in leaves and roots under salt stress.（3）Subcellular localization results showed that PagERF114 protein was localized in the cell membrane and nucleus.The results of yeast transcriptional activation activity experiments showed that PagERF114 gene had no transcriptional activation activity.Through yeast two-hybridization experiment,the interaction protein LTP16 of PagERF114 protein was found.（4）Eight PagERF114-OE overexpression transgenic strains were obtained.PagERF114-OE and WT were treated using a saline solution of 150 mmol/L.The stress time was 7 days,and we measured the growth traits and physiological indicators.In the salt stress,the result is that H₂O₂content and MDA content of PagERF114-OE were lower than WT,and the activities of SOD and POD were significantly higher than WT.The results showed that the PagERF114-OE improved the salt tolerance.It not only reduces the accumulation of H₂O₂and MDA,but also improves the clearance ability of ROS inside cells and reduces the damage of ROS to cells.Tissue-specific staining results also confirm this conclusion.