title: Genome-Wide Function, Evolutionary Characterization and Expression Analysis of Sugar Transporter Family Genes in Pear (Pyrus bretschneideri Rehd).
abstract: The sugar transporter (ST) plays an important role in plant growth, development and fruit quality. In this study, a total of 75 ST genes were identified in the pear (Pyrus bretschneideri Rehd) genome based on systematic analysis. Furthermore, all ST genes identified were grouped into eight subfamilies according to conserved domains and phylogenetic analysis. Analysis of cis-regulatory element sequences of all ST genes identified the MYBCOREATCYCB1 promoter in sucrose transporter (SUT) and monosaccharide transporter (MST) genes of pear, while in grape it is exclusively found in SUT subfamily members, indicating divergent transcriptional regulation in different species. Gene duplication event analysis indicated that whole-genome duplication (WGD) and segmental duplication play key roles in ST gene amplification, followed by tandem duplication. Estimation of positive selection at codon sites of ST paralog pairs indicated that all plastidic glucose translocator (pGlcT) subfamily members have evolved under positive selection. In addition, the evolutionary history of ST gene duplications indicated that the ST genes have experienced significant expansion in the whole ST gene family after the second WGD, especially after apple and pear divergence. According to the global RNA sequencing results of pear fruit development, gene expression profiling showed the expression of 53 STs. Combined with quantitative real-time PCR (qRT-PCR) analysis, two polyol/monosaccharide transporter (PLT) and three tonoplast monosaccharide transporter (tMT) members were identified as candidate genes, which may play important roles in sugar accumulation during pear fruit development and ripening. Identification of highly expressed STs in fruit is important for finding novel genes contributing to enhanced levels of sugar content in pear fruit.
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jia-Ming
authors.initials: JM
authors.lastname: Li
authors.affiliation: Roy J. Carver Biotechnology Center, University of Illinois Urbana-Champaign, Urbana, IL, USA.
authors.forename: Dan-man
authors.initials: DM
authors.lastname: Zheng
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Lei-ting
authors.initials: LT
authors.lastname: Li
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Qiao
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shu-wei
authors.initials: SW
authors.lastname: Wei
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Bai
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shao-ling
authors.initials: SL
authors.lastname: Zhang
authors.affiliation: Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China wujun@njau.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D032461:Chromosomes, Plant / Q000235:genetics; D003062:Codon / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D005638:Fruit / Q000235:genetics; D020440:Gene Duplication; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007438:Introns / Q000235:genetics; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary; D031989:Pyrus / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D012641:Selection, Genetic; D014158:Transcription, Genetic
chemical_list: D003062:Codon; D026901:Membrane Transport Proteins
keywords: Genome duplication events; Pear (Pyrus bretschneideri Rehd); Positive selection; Sugar transporter gene family