The Nature of Oxygen in Sporopollenin from the Pollen of Typha angustifolia L.

Abstract

Native and peracetylated sporopollenin from the pollen of Typha angustifolia L. was investigated using several spectroscopic methods, inducing Fourier transform infrared spectroscopy (FTIR), solid-state 13C-nuclear magnetic resonance spectroscopy ( 13C-NMR) and Xray photoelectron spectrometry (XPS). Interpretation of the experimental data shows that the greater part of oxygen found in sporopollenin originates from hydroxyl groups and must be derived from aliphatics and not from aromatics. This result indicates that not only aromatics and long unbranched aliphatics but also poly-hydroxyl aliphatic components are involved in the complex structure of the polymer. Furthermore, it is most probable that the monomers of the sporopollenin skeleton are linked by ether- and not by ester-linkage. Two possible approaches are suggested for the characterisation of sporopollenin structure.

LAP6/POLYKETIDE SYNTHASE AandLAP5/POLYKETIDE SYNTHASE BEncode Hydroxyalkyl α-Pyrone Synthases Required for Pollen Development and Sporopollenin Biosynthesis inArabidopsis thaliana

“…These results are consistent with a sporopollenin structure that incorporates hydroxylated fatty acids coupled via ester and ether linkages (Guilford et al, 1988;Ahlers et al, 2000Ahlers et al, , 2003Morant et al, 2007;de Azevedo Souza et al, 2009), but the exact chemical nature of the sporopollenin polymer and sporopollenin precursor components still remains to be elucidated. Information on such components may come from enzymes encoded by genes that are coregulated with ACOS5 and other genes involved in sporopollenin biosynthesis.…”

Novel Phenanthrene Sorption Mechanism by Two Pollens and Their Fractions

“…The structure of the NHC fractions in pollen samples is similar to that reported for sporopollenin, which principally contains aliphatic, aromatic, ether, and carbonyl and carboxylic groups in varying degrees. 29,30,32,40 NMR spectroscopy therefore indicates that the investigated NHC fractions are the same as sporopollenin. All of these observed structures will significantly affect their affinities to HOC, which will be discussed later.…”

LAP3, a novel plant protein required for pollen development, is essential for proper exine formation

“…lap3-2 leads to a wide variety of metabolic consequences in developing anthers. Given the model of sporopollenin composed of fatty acid and phenolic compounds (Guilford et al 1988;Kawase and Takahashi 1995;Ahlers et al 1999Ahlers et al , 2000Ahlers et al , 2003Dominguez et al 1999;MeuterGerhards et al 1999;Bubert et al 2002), it is of interest to note that some changes were detected in the levels of lipids (such as a-linolenic acid, 1-18:3-lysophophatidylethanolamine, 1-16:0-lysophophatidylethanolamine, a-eleosteric acid, and 10E,12Z-octadecadienoic acid, linoleic acid, nonacosane and palmitic acid) and of at least one phenylpropanoid (naringenin chalcone).…”

“…In addition, a possibility exists that sporopollenin is not a single substance, but instead varies chemically between species and even between different stages of development (Hemsley et al 1993;Meutergerhards et al 1995). Despite these difficulties, tracer experiments, NMR and spectroscopic/spectrometric studies have yielded a model of sporopollenin composed of polyhydroxylated unbranched aliphatics and phenolics covalently coupled with ether and ester linkages (Guilford et al 1988;Kawase and Takahashi 1995;Ahlers et al 1999Ahlers et al , 2000Ahlers et al , 2003Dominguez et al 1999;Meuter-Gerhards et al 1999;Bubert et al 2002).…”