title: Structural characterization of arabinoxylans from two African plant species Eragrostis nindensis and Eragrostis tef using various mass spectrometric methods.
abstract: BACKGROUND
  The arabinoxylans are one of the main components of plant cell walls and are known to play major roles in plant tissues properties depending in particular on their structural features. It has been recently shown that one of the strategies developed by resurrection plants to overcome dehydration is based on cell wall composition. For this purpose, the structural characterization of arabinoxylans from desiccation-tolerant grass Eragrostis nindensis (E. nindensis) was compared with its close relative, the desiccation-sensitive Eragrostis tef (E. tef) in order to further understand mechansism of desiccation tolerance in resurrection plants.
  
  
  METHODS
  Ion mobility spectrometry coupled to mass spectrometry (IM-MS) in combination with the conventional mass spectrometric approaches, including matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), electrospray ionization multistage tandem mass spectrometry (ESI-MS(n)) and gas chromatography/mass spectrometry (GC/MS), were used to characterize arabinoxylan fragments obtained after endo-xylanase digestion of leave extracts from E. nindensis and E. tef.
  
  
  RESULTS
  Whole fingerprinting by MALDI-MS analysis showed the presence of various arabinoxylan fragments within leaves of E. nindensis and E. tef. The monosaccharide composition and some linkage information were determined by GC/MS experiments. Information regarding the branching and sequence details was obtained by ESI-MS(n) experiments after sample permethylation. The presence of structural isomeric ions with different collision cross sections was evidenced by IM-MS which could be differentiated using ESI-MS(n).
  
  
  CONCLUSIONS
  We have shown that an orthogonal approach, and especially IM-MS associated to ESI-MS(n) (n = 2 to 4) and GC/MS allowed characterization of arabinoxylan fragments of E. nindensis and E. tef and revealed the presence of isomeric structures. The same arabinoxylan structures were identified for both species but in different relative abundance. Moreover, this work illustrated that IM-MS can efficiently separate isomeric structures and advantageously complements the conventional mass spectrometric methodologies used for arabinoxylan structural characterization.
authors.affiliation: Laboratoire Glyco-MEV EA 4358, GRR IRIB, GRR VASI, Plateforme de Recherche en Imagerie Cellulaire de Haute-Normandie, Faculté des Sciences, Université de Rouen, 76 821, Mont saint Aignan, Cedex, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Plancot
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Vanier
authors.forename: Florian
authors.initials: F
authors.lastname: Maire
authors.forename: Muriel
authors.initials: M
authors.lastname: Bardor
authors.forename: Patrice
authors.initials: P
authors.lastname: Lerouge
authors.forename: Jill M
authors.initials: JM
authors.lastname: Farrant
authors.forename: John
authors.initials: J
authors.lastname: Moore
authors.forename: Azeddine
authors.initials: A
authors.lastname: Driouich
authors.forename: Maïté
authors.initials: M
authors.lastname: Vicré-Gibouin
authors.forename: Carlos
authors.initials: C
authors.lastname: Afonso
authors.forename: Corinne
authors.initials: C
authors.lastname: Loutelier-Bourhis
mesh_terms: D031750:Eragrostis / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014990:Xylans / Q000032:analysis* / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D014990:Xylans; C085118:arabinoxylan