Xyloglucans in the non-lignified primary cell walls of different species of monocotyledons have diverse structures, with widely varying proportions of oligosaccharide units that contain fucosylated side chains (F side chains). To determine whether fucosylated xyloglucans occur in all non-lignified walls in a range of monocotyledon species, we used immunofluorescence microscopy with the monoclonal antibody CCRC-M1. The epitope of this antibody, α-L-Fucp-(1→2)-β-D-Galp, occurs in F side chains. In most non-commelinid monocotyledons, the epitope was found in all non-lignified walls. A similar distribution was found in the palm Phoenix canariensis, which is a member of the basal commelinid order Arecales. However, in the other commelinid orders Zingiberales, Commelinales, and Poales, the occurrence of the epitope was restricted, sometimes occurring in only the phloem walls, but often also in walls of other cell types including stomatal guard and subsidiary cells and raphide idioblasts. No epitope was found in the walls of the commelinids Tradescantia virginiana (Commelinaceae, Commelinales) and Zea mays (Poaceae, Poales), but it occurred in the phloem walls of two other Poaceae species, Lolium multiflorum and L. perenne. The distribution of the epitope is discussed in relation to xyloglucan structures in the different taxa. However, the functional significance of the restricted distributions is unknown.

Compression wood has undesirable properties for structural timber and for paper production. Traditional methods of detecting it are often time consuming and subjective. This study aimed to rapidly and impartially detect compression wood through the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and diffuse reflectance near infrared (NIR) spectroscopy. Compression wood and non-compression wood samples were obtained from young Pinus radiata D. Don trees grown in New Zealand. Longitudinal dimensional changes were measured during drying or water saturation of the samples; lignin and galactose contents were determined using conventional analytical techniques. Chemical composition was here a more reliable discriminator between wood types than longitudinal dimensional changes. It was shown that partial least-squares regression (PLS-R) or discriminatory analysis (PLS-DA) could be used to build models on the training samples that could discriminate between wood types of the independently grown validation samples. Ultimately, both types of spectroscopies could be used to discriminate between compression wood and non-compression wood either through prediction or discriminatory analysis with equal success. Investigation into spectral differences between wood types, including sequential mixtures of wood types, showed that for the mid-IR region absorbance at a well-resolved lignin band could be used to discriminate compression wood from non-compression wood. For NIR, a similar investigation showed that absorbance values at four separate wavenumbers or the 6000–5600 cm⁻¹region of the first derivative spectra were required for that discrimination. It is proposed that if there is a gradual change in the chemical composition of compression wood with its severity, then IR spectroscopy could feasibly be used to rapidly determine compression wood severity.

At ripeness, the outer husk of “covered” barley grains firmly adheres to the underlying caryopsis. A cuticular cementing layer on the caryopsis is required for husk adhesion, however the quality of adhesion varies significantly among cultivars which produce the cementing layer, resulting in the economically important malting defect, grain skinning. The composition of the cementing layer, and grain organ development have been hypothesised to influence the quality of husk adhesion. Plants of Hordeum vulgare ‘Concerto’ were grown at different temperatures pre- and post-anthesis to effect changes in the development of the husk, caryopsis and cuticular cementing layer, to determine how these variables influence the quality of husk-to-caryopsis adhesion. Warm conditions pre-anthesis decreased the quality of husk adhesion, and consequently increased the incidence of grain skinning. Cool post-anthesis conditions further decreased the quality of husk adhesion. The composition of the cementing layer, rather than its structure, differed with respect to husk adhesion quality. This cementing layer was produced at the late milk stage, occurring between nine and 29 days post-anthesis, conditional on the temperature-dependent growth rate. The compounds octadecanol, tritriacontane, campesterol and β-sitosterol were most abundant in caryopses with high-quality husk adhesion. The differences in adhesion quality were not due to incompatible husk and caryopsis dimensions affecting organ contact. This study shows that husk-to-caryopsis adhesion is dependent on cementing layer composition, and implies that this composition is regulated by temperature before, and during grain development. Understanding this regulation will be key to improving husk-to-caryopsis adhesion.