title: Genome-wide identification and characterization of R2R3MYB family in Cucumis sativus.
abstract: BACKGROUND
  The R2R3MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some species, little is known about R2R3MYB genes in cucumber (Cucumis sativus L.).
  
  
  RESULTS
  This study has identified 55 R2R3MYB genes in the latest cucumber genome and the CsR2R3MYB family contained the smallest number of identified genes compared to other species that have been studied due to the absence of recent gene duplication events. These results were also supported by genome distribution and gene duplication analysis. Phylogenetic analysis showed that they could be classified into 11 subgroups. The evolutionary relationships and the intron-exon organizations that showed similarities with Arabidopsis, Vitis and Glycine R2R3MYB proteins were also analyzed and suggested strong gene conservation but also the expansions of particular functional genes during the evolution of the plant species. In addition, we found that 8 out of 55 (∼14.54%) cucumber R2R3MYB genes underwent alternative splicing events, producing a variety of transcripts from a single gene, which illustrated the extremely high complexity of transcriptome regulation. Tissue-specific expression profiles showed that 50 cucumber R2R3MYB genes were expressed in at least one of the tissues and the other 5 genes showed very low expression in all tissues tested, which suggested that cucumber R2R3MYB genes took part in many cellular processes. The transcript abundance level analysis during abiotic conditions (NaCl, ABA and low temperature treatments) identified a group of R2R3MYB genes that responded to one or more treatments.
  
  
  CONCLUSIONS
  This study has produced a comparative genomics analysis of the cucumber R2R3MYB gene family and has provided the first steps towards the selection of CsR2R3MYB genes for cloning and functional dissection that can be used in further studies to uncover their roles in cucumber growth and development.
authors.affiliation: State Key Laboratory of Crop Biology, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Cunjia
authors.initials: C
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.forename: Zhonghai
authors.initials: Z
authors.lastname: Ren
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics; D018553:Cucumis sativus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005091:Exons / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics*; D007438:Introns / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid