The Analysis Of SBP-box Gene Family And Genetic Transformation Of Cucumber

Cucumber(Cucumis sativus L.)is an important vegetable crop with extremely high economic value and it has been widely cultivated all over the world.The development of its lateral meristem directly affects the yield,quality and economic benefits and thus,regulating the development of cucumber lateral meristem is of great significance for the increase of yield and efficiency.The SBP-box gene family is a plant-specific family of transcription factors.It is widely involved in plant growth and development,and has become a key regulatory factor in various biological processes of plants,including the time of changes at nutritional and reproductive stages,leaf development,tillering/branching,sculpting cells,panicle/tassel structure,fruit maturation,fertility and response to stress.However,the gene function of the SBP-box gene family in cucumber is not clear,and there is no research on the development of cucumber lateral meristem.Therefore,the analysis and prediction of the SBP gene that controls the development of cucumber lateral meristems through bioinformatics methods,and the verification of gene function through reverse genetics(gene editing)have important theoretical research value and production practice significance.Major research results are presented below:1.The bioinformatics analysis of cucumber SBP-box family genes was conducted.Fourteen SBP-box genes were identified in cucumber and they distributed on four chromosomes.Sequence analysis showed that this gene family members contained a conserved domain of about 76 amino acids,two zinc finger structures with C3 H and C2 HC and a nuclear localization signal.The phylogenetic tree analysis showed that cucumber SBP-box gene could be divided into five groups and among them,the cucumber SBP-box had a closer relationship with the evolution of dicotyledonous plants.In addition,collinear analysis showed there were 5 pairs of homologous genes in cucumber genome and 14 pairs of homologous genes in cucumber and Arabidopsis genome.2.The tissue expression characteristics of cucumber SBP-box family genes were analyzed.The results showed that the expression patterns of cucumber SBP-box gene in various tissues could be divided into two categories,i.e.constitutive expression and differential expression.Moreover,constitutive expression genes had a low level of expression in each issue tested.In short,cucumber Cs SBP09 genes had the highest expression level in tendril and the lowest expression level in root,with the rest falling in between.3.The existing cucumber transgenic system was optimized and a suitable cucumber material CG1 was selected.The optimum co-culture temperature and time were 23? and 4d respectively.After differentiation,screening and pressure exploration,it was found that the transgenic efficiency was the highest when the concentration of phosphosate was 1.5 mg/L,which could reach 1.0%.4.The single and double target sit gene editing vector for relevant gene Cs SBP09 that are related to predicting lateral meristem development was constructed and genetic transformation of cucumber was conducted.The results of genetic transformation indicated that GFP positive plants were obtained and no editing effect occurred.The gene Cs SBP09 that were related to lateral meristem development needed further investigation.