The Identification、Expression Analysis Of Apple BZIP Family Genes And Functional Study Of Grape WRKY48 Gene

Apple（Malus domestica）and grape（Vitis Vinifera）are important economic fruit tree in the world,which have been widely cultivated in many country.However,they often were threatened by the bad environment,thus reduce their production and the quality of the fruit.Digging and using the stress-related genes in fruit tree are important for cultivating new varieties,that are resistant to various suroundings.Plant bZIP and WRKY transcription factor genes are widely reported to involve in their growth and development in many plants,as well as their response to biotic/abiotic stresses.Previously,47 bZIP and 59 WRKY transcription factor family genes were identificated and analysed from grape genome,and 127 WRKY family genes also were found and analysed in apple genome.However,genome analyse of bZIP family genes in apple were not reported.On the basis,our research identificated 112 MdbZIP genes from apple genome,and analysed their evolution relationships and expression patterns,aimed to find the candidate good genes for apple genetic engineering breeding.On the other hand,our research cloned one grape gene WRKY48 from V.labrusca×V.vinifera cv.Kyoho,and constructed the over-expression vector of pCAMBIA2300-35S-VlWRKY48,then transferred it into the Arabidopsis thaliana.Which revealed the function of the gene in drought and powdery mildew.The main results were described as follows:1.We identified 112 apple bZIP TF-encoding genes from apple genome,termed MdbZIP genes.Synteny analysis indicated that segmental and tandem duplication events,as well as whole genome duplication,have contributed to the expansion of the apple bZIP family.Syntenic analyses between A.thaliana and apple genome was performed,a total of 21 A.thaliana bZIP genes and 19 apple genes were identified as syntenic orthologs.Of these,6 gene pairs appeared to be single apple-to-A.thaliana gene pairs,indicating that these genes were likely present in the genome of the last common ancestor of these two species.According to the phylogenetic tree,the apple MdbZIP proteins could be divided into 11 groups,which was A,B,C,D,E,F,G,H,I,J,S.Exon/intron structure showed that Exon/intron gain/loss also were occurred in apple bZIP transcription factors family,which might diversify the function of the apple gene.Most group-A bZIP genes were expressed in various organs,and after treated with drought,salt and plant hormone,they were up-regulated or down-regulated.2.The cDNA sequence of grape gene WRKY48 from V.labrusca×V.vinifera cv.Kyoho was cloned using revise RT-PCR.GeneBank accession number of VlWRKY48 was XM₀02280995.2,and the open reading frame were predicted to have 1,050 bp nucleic acids,which encoded a 349 amino acid residues.The protein also was found to have one conserved WRKY domain and a C2 HC zinc-finger motif within their predicted sequence,which belongs to Group III sub-family.After over-expressed VlWRKY48 in A.thaliana,the transgenic plants showed the increased tolerance to drought treatment during germination,seedlings and four-week-old mature stage.In addition,transgenic plants also showed the increased resistance to powdery midelw,and the expression of stress-related genes indicated the VlWRKY48 might play positive roles in SA pathway to response to the powdery midelw.