title: Transcriptome Analysis of Flower Sex Differentiation in Jatropha curcas L. Using RNA Sequencing.
abstract: BACKGROUND
  Jatropha curcas is thought to be a promising biofuel material, but its yield is restricted by a low ratio of instaminate/staminate flowers (1/10-1/30). Furthermore, valuable information about flower sex differentiation in this plant is scarce. To explore the mechanism of this process in J. curcas, transcriptome profiling of flower development was carried out, and certain genes related with sex differentiation were obtained through digital gene expression analysis of flower buds from different phases of floral development.
  
  
  RESULTS
  After Illumina sequencing and clustering, 57,962 unigenes were identified. A total of 47,423 unigenes were annotated, with 85 being related to carpel and stamen differentiation, 126 involved in carpel and stamen development, and 592 functioning in the later development stage for the maturation of staminate or instaminate flowers. Annotation of these genes provided comprehensive information regarding the sex differentiation of flowers, including the signaling system, hormone biosynthesis and regulation, transcription regulation and ubiquitin-mediated proteolysis. A further expression pattern analysis of 15 sex-related genes using quantitative real-time PCR revealed that gibberellin-regulated protein 4-like protein and AMP-activated protein kinase are associated with stamen differentiation, whereas auxin response factor 6-like protein, AGAMOUS-like 20 protein, CLAVATA1, RING-H2 finger protein ATL3J, auxin-induced protein 22D, and r2r3-myb transcription factor contribute to embryo sac development in the instaminate flower. Cytokinin oxidase, Unigene28, auxin repressed-like protein ARP1, gibberellin receptor protein GID1 and auxin-induced protein X10A are involved in both stages mentioned above. In addition to its function in the differentiation and development of the stamens, the gibberellin signaling pathway also functions in embryo sac development for the instaminate flower. The auxin signaling pathway also participates in both stamen development and embryo sac development.
  
  
  CONCLUSIONS
  Our transcriptome data provide a comprehensive gene expression profile for flower sex differentiation in Jatropha curcas, as well as new clues and information for further study in this field.
authors: Research Institute of Forest Resources and Environment, Guizhou University, Guiyang, Guizhou, P. R. China.|Institute of Entomology, Guizhou University, Guiyang, Guizhou, P. R. China.
authors: Gang
authors: G
authors: Xu
authors: Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals of Guizhou University, Guiyang, Guizhou, P. R. China.
authors: Jian
authors: J
authors: Huang
authors: Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals of Guizhou University, Guiyang, Guizhou, P. R. China.
authors: Yong
authors: Y
authors: Yang
authors: School of life science and engineering, Southwest University of Science and Technology, Mianyang, Sichuan, P. R. China.
authors: Yin-an
authors: YA
authors: Yao
mesh_terms: D019295:Computational Biology / Q000379:methods; D030541:Databases, Genetic; D035264:Flowers / Q000235:genetics* / Q000648:ultrastructure; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D059014:High-Throughput Nucleotide Sequencing; D031286:Jatropha / Q000235:genetics*; D058977:Molecular Sequence Annotation; D063246:Organogenesis, Plant / Q000235:genetics; D010641:Phenotype; D017423:Sequence Analysis, RNA; D059467:Transcriptome