Genome-wide Identification And Function-structure Analysis Of Ubiquitin-conjugating E2 Genes Family In Grape

Grape(Vitis vinifera)is widely cultivated in our country even in the world,which has important economic value.During the growth and development,grape is easily suffering various abiotic stress,such as heat,drought,cold,high-salinity.The ripening process is essential for the quality of grape fruit and wine,which is regulated by various factors.Ubiquitination is an important pathway of protein modification and universally exist in all eukaryote.Uniquitin-conjugating enzyme E2 is an important participant in ubiquitination,and is characterized by UBC(ubiquitin-conjugating)domain.Based on the whole genome sequence of Pinot Noir(Vitis vinifera,PN40024),43 E2 genes were identified from grape genome and were further analyzed with their functions and structures.In order to provide a foundation for the research of E2 genes in grape growth and development,expression patterns of E2 genes were explored in grape ripening process and abiotic stress.Main research results are as follows:1.According to BLAST method,combining HMM model and protein domain analysis,43 E2 genes members were identified from grape whole genome database.Phylogenetic tree was constructed using E2 gene members in tomato and grape,and E2 genes in grape were grouped in five base on the tree,then were named as VvUBC1a–VvUBC52 base on the relationship of E2 genes between grape and tomato in phylogenetic tree.2.VvUBCs were divided into four Class according to the existence of protein extension besides UBC domain: most VvUBCs(28 members)possess a single UBC domain and are categorized as Class I;Class II(three members)features an N-terminal extension;Class III(six members)presents a C-terminal extension;and Class IV(six members)exhibits both extensions.3.VvUBCs in the same Group own similar motifs;forty-three VvUBCs distribute in 19 chromosome except chromosome 10 of grape,there are big differences in the intron-proportion,gene length and promoter location between VvUBCs;whole genome duplication events result in the expand of grape E2 genes to a great extent.4.Analysis of expression patterns in grape ripening process were performed,most VvUBCs are up-regulated or down-regulated during fruit ripening in grape,which indicating the important roles of VvUBCs during ripening process.In addition,seven VaUBCs respond to cold stress,six E2 genes in Cabernet Sauvignon(Vitis vinifera)and spine grape(Vitis davidii)both respond to heat stress.These genes may be involved in the regulation mechanism under cold and heat stress in grape.