title: Profiling of hydroxycinnamic acid amides in Arabidopsis thaliana pollen by tandem mass spectrometry.
abstract: Phenylpropanoid polyamine conjugates are widespread in plant species. Their presence has been established in seeds, flower buds, and pollen grains. A biosynthetic pathway proposed for hydroxycinnamoyl spermidine conjugates has been suggested for the model plant Arabidopsis thaliana with a central acyl transfer reaction performed by a BAHD-like hydroxycinnamoyl transferase. A detailed liquid chromatography (LC)-electrospray ionization-mass spectrometry- and tandem-mass-spectrometry (MS/MS)-based survey of wild-type and spermidine hydroxycinnamoyl transferase (SHT) mutants identified more than 30 different bis- and tris-substituted spermidine conjugates, five of which were glycosylated, in the methanol-soluble fraction of the pollen exine. On the basis of characterized fragmentation patterns, a high-throughput LC-MS/MS method for highly sensitive HCAA relative quantification (targeted profiling) was developed. Only minor qualitative and quantitative differences in the pattern of bis-acyl spermidine conjugates in the SHT mutant compared to wild-type plants provide strong evidence for the presence of multiple BAHD-like acyl transferases and suggest a much more complex array of enzymatic steps in the biosynthesis of these conjugates than previously anticipated.
authors.affiliation: Department of Secondary Metabolism, Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany.
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Handrick
authors.forename: Thomas
authors.initials: T
authors.lastname: Vogt
authors.forename: Andrej
authors.initials: A
authors.lastname: Frolov
mesh_terms: D000577:Amides / Q000032:analysis*; D017360:Arabidopsis / Q000737:chemistry*; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D003373:Coumaric Acids / Q000032:analysis*; D011058:Pollen / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D000577:Amides; D003373:Coumaric Acids