title: Transcriptome assembly and analysis of Tibetan Hulless Barley (Hordeum vulgare L. var. nudum) developing grains, with emphasis on quality properties.
abstract: BACKGROUND
  Hulless barley is attracting increasing attention due to its unique nutritional value and potential health benefits. However, the molecular biology of the barley grain development and nutrient storage are not well understood. Furthermore, the genetic potential of hulless barley has not been fully tapped for breeding.
  
  
  RESULTS
  In the present study, we investigated the transcriptome features during hulless barley grain development. Using Illumina paired-end RNA-Sequencing, we generated two data sets of the developing grain transcriptomes from two hulless barley landraces. A total of 13.1 and 12.9 million paired-end reads with lengths of 90 bp were generated from the two varieties and were assembled to 48,863 and 45,788 unigenes, respectively. A combined dataset of 46,485 All-Unigenes were generated from two transcriptomes with an average length of 542 bp, and 36,278 among were annotated with gene descriptions, conserved protein domains or gene ontology terms. Furthermore, sequences and expression levels of genes related to the biosynthesis of storage reserve compounds (starch, protein, and β-glucan) were analyzed, and their temporal and spatial patterns were deduced from the transcriptome data of cultivated barley Morex.
  
  
  CONCLUSIONS
  We established a sequences and functional annotation integrated database and examined the expression profiles of the developing grains of Tibetan hulless barley. The characterization of genes encoding storage proteins and enzymes of starch synthesis and (1-3;1-4)-β-D-glucan synthesis provided an overview of changes in gene expression associated with grain nutrition and health properties. Furthermore, the characterization of these genes provides a gene reservoir, which helps in quality improvement of hulless barley.
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China; College of Life Sciences, Sichuan University, Chengdu, Sichuan, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Long
authors.affiliation: College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Gao
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.
authors.forename: Guangbing
authors.initials: G
authors.lastname: Deng
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.
authors.forename: Zhifen
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.
authors.forename: Junjun
authors.initials: J
authors.lastname: Liang
authors.affiliation: Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet, China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet, China.
authors.forename: Nyima
authors.initials: N
authors.lastname: Tashi
authors.affiliation: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.
authors.forename: Maoqun
authors.initials: M
authors.lastname: Yu
mesh_terms: D001483:Base Sequence; D020869:Gene Expression Profiling; D063990:Gene Ontology; D001467:Hordeum / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D055314:Seed Storage Proteins / Q000235:genetics; D017423:Sequence Analysis, RNA; D013045:Species Specificity; D013213:Starch / Q000096:biosynthesis; D059467:Transcriptome / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D055314:Seed Storage Proteins; D013213:Starch