Genome-Wide Analysis Of WOX Gene Family And Functional Research Of TaWUS In Wheat

WUSCHEL-related homeobox(WOX)family is a family of transcription factors that are unique to plants,which is characterized by the presence of homodomain.WOX genes play essential roles in regulating the developmental decision of plant tissues and organs.Wheat(Triticum aestivum L.)is one of the important food crops in the world.In this study,WOX gene family in wheat were obtained by bioinformatics analysis.The evolution,expression pattern of WOX genes was analyzed by bioinformation strategy.Further,the function of Ta WUSB was investigated through forward genetics methods.The main result was as below:The genome-wide search were performed using HMMER3.0 with the Hiden Markov model of At WOXs as query.80 candidate WOX sequences were obtained in the databases of Ensemblplants.Among them,A,B,and D genome contains 23,26,and 29 WOX genes,respectively.In addition,the location of 2 WOX genes was not clear.Phylogenetic tree analysis showed that these WOX genes were grouped into 3 clades,i.e.ancient clade,intermediate clade and modern clade.Analysis of homodomain indicated that the helix contains highly conserved amino acid residues.qRT-PCR results indicated that the paralogs from A,B and D genome presented similar expression patterns.Based the expect value of BLAST,Phylogenetic tree analysis and domain identification as well as expression patternanalyses,homologs of At WUS in wheat were identified,and then named as TaWUSA,TaWUSB and TaWUSD.Subcellular localization experiment showed Ta WUSB localization in the nucleus.In order to further understand the expression site of Ta WUSB,the in situ hybridization experiment was conducted,and the results showed that Ta WUS genes were expressed in the shoot apical meristem and young leaves with high level.To further analyze Ta WUS gene function,we constructed the Ta WUSBoverexpression vector and transformed wild Arabidopsis plants.The transgenic plants showed the phenotypes that increased cauline leaf inflorescence branches with curled cauline leaves and pistil agensis.To investigate TaWUS function in wheat,TaWUSB-overexpression vector was transformed into wheat plants with Agrobacterium-mediated transformation strategy using the immature embryos of CB037 plants.Interestingly,all the transformant showed similar phenotypes with altered plant architecture.Almost all the high node bearing extra spikes.The results indicated that high level of TaWUSB expression could promote the continuous development of high-node axillary meristem cells,suggesting that TaWUSB could promote stem cell activity of the axillary meristem.The phenotype provide important clues for further analysis of Ta WUS function in regulating the development of wheat,especially the spike(inflorescence)architecture.In this study,the WOX gene family was classified and identified through the analysis of whole-genome sequence of wheat,and the function of Ta WUSB was preliminarily analyzed in Arabidopsis and wheat.The experimental results provide new information for investgating the molecular mechanism of WOX gene in regulation of wheat development.