title: Transcriptome analysis of Salicornia europaea under saline conditions revealed the adaptive primary metabolic pathways as early events to facilitate salt adaptation.
abstract: BACKGROUND
  Halophytes such as Salicornia europaea have evolved to exhibit unique mechanisms controlled by complex networks and regulated by numerous genes and interactions to adapt to habitats with high salinity. However, these mechanisms remain unknown.
  
  
  METHODS
  To investigate the mechanism by which halophytes tolerate salt based on changes in the whole transcriptome, we performed transcriptome sequencing and functional annotation by database search. Using the unigene database, we conducted digital gene expression analysis of S. europaea at various time points after these materials were treated with NaCl. We also quantified ion uptakes. Gene functional enrichment analysis was performed to determine the important pathways involved in this process.
  
  
  RESULTS
  A total of 57,151 unigenes with lengths of >300 bp were assembled, in which 57.5% of these unigenes were functionally annotated. Differentially expressed genes indicated that cell wall metabolism and lignin biosynthetic pathways were significantly enriched in S. europaea to promote the development of the xylem under saline conditions. This result is consistent with the increase in sodium uptake as ions pass through the xylem. Given that PSII efficiency remained unaltered, salt treatment activated the expression of electron transfer-related genes encoded by the chloroplast chromosome. Chlorophyll biosynthesis was also inhibited, indicating the energy-efficient state of the electron transfer system of S. europaea.
  
  
  CONCLUSIONS
  The key function of adjusting important primary metabolic pathways in salt adaption was identified by analyzing the changes in the transcriptome of S. europaea. These pathways could involve unique salt tolerance mechanisms in halophytes. This study also provided information as the basis of future investigations on salt response genes in S. europaea. Ample gene resources were also provided to improve the genes responsible for the salt tolerance ability of crops.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, P.R. China.
authors.forename: Pengxiang
authors.initials: P
authors.lastname: Fan
authors.forename: Lingling
authors.initials: L
authors.lastname: Nie
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Feng
authors.forename: Sulian
authors.initials: S
authors.lastname: Lv
authors.forename: Xianyang
authors.initials: X
authors.lastname: Chen
authors.forename: Hexigeduleng
authors.initials: H
authors.lastname: Bao
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.forename: Fang
authors.initials: F
authors.lastname: Tai
authors.forename: Jinhui
authors.initials: J
authors.lastname: Wang
authors.forename: Weitao
authors.initials: W
authors.lastname: Jia
authors.forename: Yinxin
authors.initials: Y
authors.lastname: Li
mesh_terms: D019663:Chenopodiaceae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D016000:Cluster Analysis; D019295:Computational Biology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D053858:Metabolic Networks and Pathways; D058977:Molecular Sequence Annotation; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D014157:Transcription Factors; D012965:Sodium Chloride