Plant spore walls as a record of long-term changes in ultraviolet-B radiation

The impact of oxidation on spore and pollen chemistry

“…To replicate previous analyses on modern material with FTIR (e.g. Lomax et al, 2008;Fraser et al, 2011) we also treated a set of replicates with acetone ([CH 3 ] 2 CO), washing the sample and removing the supernatant four times, and allowing the samples to air dry. In total we produced 228 samples for chemical analysis (two oxidizing agents × two heat levels × nine time intervals × six replicates, plus the 12 control samples).…”

“…UV-B absorbing compounds are detected in IR spectra via an absorbance peak that occurs near 1510 cm -1 , caused by the stretching by guest on May 10, 2018 http://jm.lyellcollection.org/ Downloaded from of C=C bonds in the aromatic ring structure (Watson et al, 2007;Fraser et al, 2014b), and have previously been quantified via a ratio with the broad hydroxyl absorbance band that centres on 3300 cm -1 (Fig. 1) (Lomax et al, 2008Fraser et al, 2011). Following Steemans et al (2010) and Fraser et al (2014b), we also examine a number of other peak height ratios that provide direct information on the balance among aliphatic, aromatic and carboxyl functional groups.…”

Environmental Monitoring and Research in the Abisko Area—An Overview

“…The data have been used in studies of UV-B radiation trends (Lindfors 2002) and UV-B radiation impacts on vegetation (Lomax et al 2008;Fraser et al 2011). …”

A novel palaeoaltimetry proxy based on spore and pollen wall chemistry

“…Sporopollenin, the biopolymer that makes up the exine (outer wall) of spores and pollen, can be broadly grouped as fatty acids (containing unbranched aliphatic chains) and phenolic components, FA and pCA (containing aromatic rings) which provide protection against UV-B (van Bergen, 2004;Watson et al, 2007;Lomax et al, 2008;Fraser et al, 2011). Fourier transform infrared (FTIR) microspectroscopy can be used to detect and identify the type of bond/functional group present based on wavenumber of the band, whilst variations in band height and area represent changes in the relative abundance of such bonds/groups.…”

“…Fourier transform infrared (FTIR) microspectroscopy can be used to detect and identify the type of bond/functional group present based on wavenumber of the band, whilst variations in band height and area represent changes in the relative abundance of such bonds/groups. To determine the relative abundance of individual functional groups of interest, FTIR spectra analyses are normalised to an internal stable absorption band, thus enabling inter-comparison of spectra by investigating relative changes in abundance of bonds/functional groups (Watson et al, 2007;Lomax et al, 2008;Fraser et al, 2011). The absorbance band due to the hydroxyl (OH) groups is chosen for normalisation both because of its stability and because the absolute IR-absorption is proportional to the quantity of sample analysed for each spectrum.…”