title: Identification of conserved and novel microRNAs from Liriodendron chinense floral tissues.
abstract: BACKGROUND
  Liriodendron chinense (L. chinense) is an endangered basal angiosperm plant in China because of its low reproductive efficiency. Recently, miRNAs have obtained great attention because they can play important roles. Through high throughput sequencing technique, large amount of miRNAs were identified from different plant species. But there were few studies about the miRNAs in the basal angiosperms especially in the sexual reproduction process.
  
  
  RESULTS
  Deep sequencing technology was applied to discover miRNAs in L. chinense flowers at different stages. After bioinformatic analysis, 496 putative conserved miRNAs representing 97 families and 2 novel miRNAs were found. Among them, one is previously regarded as gymnosperm specific. Their expressions were further validated by Real-time PCR for 13 selected miRNAs. Putative targeting genes were predicted and categorized with gene ontology (GO) analysis. About ten percents of the targets are involved in the reproduction process. Further expressional analysis showed that many of these miRNAs were highly related to the reproductive growth.
  
  
  CONCLUSIONS
  This is the first comprehensive identification of conserved and novel miRNAs in L. chinense. The data presented here might not only help to fill the gap of miRNA registered about basal angiosperm plants but also contribute to understanding the evolution of miRNAs. The differential expression of some of the miRNAs and the prediction of their target genes are also helpful in understanding the regulation of L. chinense sexual reproduction.
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden of Chinese Academy of Sciences, Wuhan, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Li
authors.forename: Yingguo
authors.initials: Y
authors.lastname: Zhu
authors.forename: Pingfang
authors.initials: P
authors.lastname: Yang
mesh_terms: D019295:Computational Biology; D035264:Flowers / Q000235:genetics* / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D031567:Liriodendron / Q000235:genetics* / Q000502:physiology; D035683:MicroRNAs / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant