title: Compositional characterization and imaging of "wall-bound" acylesters of Populus trichocarpa reveal differential accumulation of acyl molecules in normal and reactive woods.
abstract: Acylesterification is one of the common modifications of cell wall non-cellulosic polysaccharides and/or lignin primarily in monocot plants. We analyzed the cell-wall acylesters of black cottonwood (Populus trichocarpa Torr. & Gray) with liquid chromatography-mass spectrometry (LC-MS), Fourier transform-infrared (FT-IR) microspectroscopy, and synchrotron infrared (IR) imaging facility. The results revealed that the cell wall of dicotyledonous poplar, as the walls of many monocot grasses, contains a considerable amount of acylesters, primarily acetyl and p-hydroxycinnamoyl molecules. The "wall-bound" acetate and phenolics display a distinct tissue specific-, bending stress responsible- and developmental-accumulation pattern. The "wall-bound" p-coumarate predominantly accumulated in young leaves and decreased in mature leaves, whereas acetate and ferulate mostly amassed in the cell wall of stems. Along the development of stem, the level of the "wall-bound" ferulate gradually increased, while the basal level of p-coumarate further decreased. Induction of tension wood decreased the accumulation of the "wall-bound" phenolics while the level of acetate remained constant. Synchrotron IR-mediated chemical compositional imaging revealed a close spatial distribution of acylesters with cell wall polysaccharides in poplar stem. These results indicate that different "wall-bound" acylesters play distinct roles in poplar cell wall structural construction and/or metabolism of cell wall matrix components.
authors.affiliation: Department of Biology, Brookhaven National Laboratory, Upton, NY 11973, USA.
authors.forename: Jin-Ying
authors.initials: JY
authors.lastname: Gou
authors.forename: Simone
authors.initials: S
authors.lastname: Park
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Yu
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Miller
authors.forename: Chang-Jun
authors.initials: CJ
authors.lastname: Liu
mesh_terms: D000215:Acylation; D002473:Cell Wall / Q000737:chemistry*; D003373:Coumaric Acids / Q000032:analysis; D004952:Esters / Q000032:analysis*; D008031:Lignin / Q000378:metabolism; D009928:Organ Specificity; D032107:Populus / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D014934:Wood / Q000378:metabolism*
chemical_list: D003373:Coumaric Acids; D004952:Esters; C036909:lignocellulose; D008031:Lignin; C004999:ferulic acid