Cloning And Function Study Of Glutathione Peroxidase TaGPX2 Gene In Wheat(Triticum Aestivum)

Wheat is one of the most important food crops in the world,and the importance of increasing its yield and improving its quality is beyond doubt.At present,the production of wheat all over the world is restricted to a certain extent by environmental stress.In China,the main producing area of wheat is in the north,which is affected by the adverse natural environment such as drought,saline-alkali land and low temperature in recent years.Therefore,it is very important to study the resistance of wheat to stress and cultivate wheat varieties resistant to stress.Saline-alkali soil exists in large quantities in the north of China,which has greatly affected the development of wheat cultivated land and wheat production.Salt stress can destroy the dynamic balance of active oxygen species in wheat,resulting in the increase of active oxygen species,adverse biological effects and strong oxidative damage to the plant.Glutathione peroxidase(GPX)is one of the important enzymes in wheat to remove reactive oxygen species,which can remove excessive reactive oxygen species in time,and greatly alleviate the damage of reactive oxygen species on wheat under stress.However,the systematic analysis of wheat GPX gene and its mechanism of function under stress are still lacking.We identified the gene family members from the whole genome of common wheat and conducted biosignal analysis.qRT-PCR analysis of their expression under stress,yeast two-hybrid assay and sub-cellular localization analysis were performed to further study the function and function mechanism of TaGPX2 gene.The main research results are as follows:(1)Identification and bioinformatics analysis of GPX gene family in wheatFourteen TaGPX genes of wheat,five TuGPX genes of Triticum urartu and five AeGPX genes of Aegilops tauschii were identified by pBLAST using known GPX protein sequences of rice and Arabidopsis,respectively.The protein sequences of TaGPX,TuGPX,AeGPX,OsGPX and AtGPX were put together for phylogenetic analysis,and they were divided into 3 subgroups according to their homology.Members of the same subgroup were more similar in gene structure and motif motif.Chromosome localization of all TaGPX members of wheat was analyzed,and it was found that they were mainly distributed on chromosomes 2,4,6 and 7.Through the analysis of transcriptome expression profile,it was found that the function of resistance to abiotic stress was more prominent,but the function of resistance to biotic stress was not obvious.The analysis of cis-acting elements in promoter region showed that TaGPX genes contained many cis-acting elements related to abiotic stress resistance.Homology analysis showed that TaGPX genes in wheat had high homology with some genes in rice and Aegilops tauschii.(2)Expression analysis of TaGPXAccording to the results of transcriptome analysis,the genes with prominent stress resistance functions were selected from all the members for further functional analysis of salt stress resistance.According to the results of qRT-PCR,TaGPX1,TaGPX2,TaGPX7,TaGPX14 had significant resistance to salt stress,and the expression levels of these genes under salt stress were significantly higher than control.(3)Interaction and subcellular localization of TaGPX2 geneIn order to further study the function mechanism of TaGPX2 under salt stress,protein interaction prediction was carried out and the prediction results showed that TaGPX2 might interact with genes HZ2 and PER1.Further verification was conducted by yeast two-hybrid assay and it was found that neither of them had interaction with TaGPX2.TaGPX2 was transiently transferred into tobacco for subcellular localization and the result showed that it might function in the cell membrane and nucleus.