Identification of unconjugated N-glycans in strawberry plants

Strawberry plants were tested for their unconjugated N-glycan (UNG) content. These molecules were found in only 3 cases: in the root, the crown and in the red fruit. Their identification was realized with both high performance anion exchange chromatography with pulsed amperometric detection and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Analysis revealed a series of oligomannosides from Man(5)GlcNAc to Man(9)GlcNAc in crowns, roots and fruit. Two supplementary complex UNGs Man(3)XylGlcNAc(2) and Man(3)XylFucGlcNAc(2) were also detected in the fruit. Quantitatively, the highest UNG content (11 mu g g(-1) fresh weight) was found in the fruit. In conclusion, we demonstrated that UNGs are not only present in tomato but also in strawberry plant.