title: Comparison of celery (Apium graveolens L.) collenchyma and parenchyma cell wall polysaccharides enabled by solid-state (13)C NMR.
abstract: Collenchyma cells with their thickened walls are one of specific mechanical support tissues for plants, while parenchyma cells are thin walled and serve multiple functions. The parenchyma tissue is what you enjoy eating, while collenchyma, because of its fibrous nature, is not so attractive. Celery is a useful model for comparing the cell walls (CWs) of the two cell types such as collenchyma and parenchyma. However, to date, the structural characteristics of collenchyma and parenchyma cell walls from the same plant have not been compared. Monosaccharide composition suggested the collenchyma cell walls contained less pectin but more hemicellulose in comparison to parenchyma. High-resolution solid-state NMR spectra of highly mobile pectins revealed that the arabinan signals were more evident in the collenchyma spectrum, while galactan showed a much stronger resonance in the parenchyma spectrum. In addition, methyl esterified and non-esterified galacturonic acid signals were observed in parenchyma CWs, but only the latter one appeared in the collenchyma. The ratio of cellulose surface/interior obtained from CP/MAS spectra for collenchyma suggested the cellulose microfibrils were ~2.4 nm, while in the parenchyma, these were somewhat larger. X-ray diffraction indicated the size of the cellulose microfibrils were the same for both types of CWs.
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand; Centre for NMR, School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. Electronic address: z.zujovic@auckland.ac.nz.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Zujovic
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
authors.forename: Da
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Melton
mesh_terms: D000077102:Apium / Q000737:chemistry / Q000166:cytology*; D002473:Cell Wall / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D011134:Polysaccharides; C030080:araban; C007916:hemicellulose; D010368:Pectins
keywords: Apium graveolens; Cell wall; Collenchyma; Parenchyma; Solid-state NMR