title: Genome-Wide Identification, Phylogenetic and Expression Analyses of the Ubiquitin-Conjugating Enzyme Gene Family in Maize.
abstract: BACKGROUND
  Ubiquitination is a post-translation modification where ubiquitin is attached to a substrate. Ubiquitin-conjugating enzymes (E2s) play a major role in the ubiquitin transfer pathway, as well as a variety of functions in plant biological processes. To date, no genome-wide characterization of this gene family has been conducted in maize (Zea mays).
  
  
  RESULTS
  In the present study, a total of 75 putative ZmUBC genes have been identified and located in the maize genome. Phylogenetic analysis revealed that ZmUBC proteins could be divided into 15 subfamilies, which include 13 ubiquitin-conjugating enzymes (ZmE2s) and two independent ubiquitin-conjugating enzyme variant (UEV) groups. The predicted ZmUBC genes were distributed across 10 chromosomes at different densities. In addition, analysis of exon-intron junctions and sequence motifs in each candidate gene has revealed high levels of conservation within and between phylogenetic groups. Tissue expression analysis indicated that most ZmUBC genes were expressed in at least one of the tissues, indicating that these are involved in various physiological and developmental processes in maize. Moreover, expression profile analyses of ZmUBC genes under different stress treatments (4°C, 20% PEG6000, and 200 mM NaCl) and various expression patterns indicated that these may play crucial roles in the response of plants to stress.
  
  
  CONCLUSIONS
  Genome-wide identification, chromosome organization, gene structure, evolutionary and expression analyses of ZmUBC genes have facilitated in the characterization of this gene family, as well as determined its potential involvement in growth, development, and stress responses. This study provides valuable information for better understanding the classification and putative functions of the UBC-encoding genes of maize.
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Dengwei
authors.initials: D
authors.lastname: Jue
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Xuelian
authors.initials: X
authors.lastname: Sang
authors.affiliation: Maize Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, 530227, China.
authors.forename: Shengqiao
authors.initials: S
authors.lastname: Lu
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Dong
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Qiufang
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Tropical Fruit Biology (Ministry of Agriculture), South Subtropical Crops Research Institute, Chinese Academy of Tropical Agricultural Sciences, Zhanjiang, 524091, China.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Jia
mesh_terms: D020816:Amino Acid Motifs; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D019295:Computational Biology / Q000379:methods; D017124:Conserved Sequence; D020440:Gene Duplication; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D055106:Genome-Wide Association Study; D005810:Multigene Family; D009928:Organ Specificity; D010802:Phylogeny; D013312:Stress, Physiological / Q000235:genetics; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics*; D003313:Zea mays / Q000145:classification* / Q000235:genetics*
chemical_list: D044763:Ubiquitin-Conjugating Enzymes