Bioinformatics And Functional Analysis Of BvCPD

BvCPD gene encodes cytochrome P450 steroid side chain hydroxylase(CYP90),which regulates the biosynthesis of brassinosteroids(BRs).To explore the function of BvCPD gene in the growth and development of sugerbeet,bioinformatics and expression analysis of different beet growth stage for its family members were carried out,the RNAi interference vector of Bv2_qyup and its overexpression vector were genetically transformed into Arabidopsis thalianarans separately.The main findings are as follows:1.BvCPD family contained 76 members,which can be clustered into 10 subgroups.Among them,the second subgroup had the most subgroup members(16).Chromosome location results showed that the BvCPD family members were distributed on all 9 chromosomes of beet,of which the most distributed is the seventh chromosome,but there were still 10 family members that had not been clearly located.There were 10 conservative motifs in the BvCPD protein,and motif 2 and motif 7 exist in all family members.2.The Bv2_qyup protein encodes 473 amino acids,has a relative molecular weight of 54.11 kDa,and an isoelectric point of 8.85.The secondary structure of the encoded protein is mainly ?-helix and random coils,which was located in the cytoplasm.It was a hydrophilic transmembrane protein containing signal peptide and has 44 phosphorylation sites.Bv2_qyup protein had high homology with the CPD of Chenopodium quinoa,Spinacia oleracea,Populus trichocarpa,Cucumis sativus and Arabidopsis thaliana.3.The expression of Bv2_qyup in different genotypes,different developmental stages and different organs of sugar beet was significantly different.In high-yield varieties,the expression level of Bv2_qyup in the seedling stage and the rapid growth stage of leaf clusters was significantly higher in leaves than in petioles and roots,and increased sharply during the root and sugar increasing stage.The expression level of Bv2_qyup in different genotypes reached its peak in the root and sugar increasing stage,and the high-yield varieties were significantly higher than which of the high-sugar varieties.4.Bv2_qyup overexpression and RNAi transgenic lines of Arabidopsis thaliana were obtained.The expression of Bv2_qyup genes in T2 transgenic plants increased,so was the endogenous BR content.Phenotypic analysis of the T2 generation transgenic lines showed that:plant height,fruit pod length,fruit pod weight,number of seeds per pod,root volume and fresh weight of the above ground were significantly higher in the overexpression lines than in the wild type,and that of wild type is significantly higher than in the RNAi lines.Leaf length,leaf area,root length and root weight were significantly higher in overexpression lines than in RNAi lines.