title: Sphingosine in plants--more riddles from the Sphinx?
abstract: • Sphingolipids are emerging as important mediators of cellular and developmental processes in plants, and advances in lipidomics have yielded a wealth of information on the composition of plant sphingolipidomes. Studies using Arabidopsis thaliana showed that the dihydroxy long-chain base (LCB) is desaturated at carbon position 8 (d18:1(Δ8)). This raised important questions on the role(s) of sphingosine (d18:1(Δ4)) and sphingosine-1-phosphate (d18:1(Δ4)-P) in plants, as these LCBs appear to be absent in A. thaliana. • Here, we surveyed 21 species from various phylogenetic groups to ascertain the position of desaturation of the d18:1 LCB, in order to gain further insights into the prevalence of d18:1(Δ4) and d18:1(Δ8) in plants. • Our results showed that d18:1(Δ8) is common in gymnosperms, whereas d18:1(Δ4) is widespread within nonseed land plants and the Poales, suggesting that d18:1(Δ4) is evolutionarily more ancient than d18:1(Δ8) in Viridiplantae. Additionally, phylogenetic analysis indicated that the sphingolipid Δ4-desaturases from Viridiplantae form a monophyletic group, with Angiosperm sequences falling into two distinct clades, the Eudicots and the Poales. • We propose that efforts to elucidate the role(s) of d18:1(Δ4) and d18:1(Δ4)-P should focus on genetically tractable Viridiplantae species where the d18:1 LCB is desaturated at carbon position 4.
authors: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors: M Nurul
authors: MN
authors: Islam
authors: INRA, UMR 320/UMR 8120 Génétique Végétale, F-91190 Gif-sur-Yvette, France.
authors: Marie-Pierre
authors: MP
authors: Jacquemot
authors: INRA, UMR 320/UMR 8120 Génétique Végétale, F-91190 Gif-sur-Yvette, France.
authors: Sylvie
authors: S
authors: Coursol
authors: School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors: Carl K-Y
authors: CK
authors: Ng
mesh_terms: D001499:Bayes Theorem; D002851:Chromatography, High Pressure Liquid; D010802:Phylogeny; D018520:Plant Shoots / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D013110:Sphingosine / Q000378:metabolism*; D009764:o-Phthalaldehyde / Q000378:metabolism
chemical_list: D009764:o-Phthalaldehyde; D013110:Sphingosine