Lloyd A. Donaldson

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Lignin is an abundant phenylpropanoid polymer produced by the oxidative polymerization of p-hydroxycinnamyl alcohols (monolignols). Lignification, i.e., deposition of lignin, is a defining feature of secondary cell wall formation in vascular plants, and provides an important mechanism for their disease resistance; however, many aspects of the cell wall(More)
Wood formation was investigated at five heights along the bole for two unrelated trees of Pinus radiata. Both trees showed clear gradients in wood properties from the base to the crown. Cambial cells at the base of the tree were dividing 3.3-fold slower than those at the crown, while the average thickness of cell walls in wood was highest at the base. Cell(More)
Suppression of the lignin-related gene cinnamoyl-CoA reductase (CCR) in the Pinus radiata tracheary element (TE) system impacted both the metabolite profile and the cell wall matrix in CCR-RNAi lines. UPLC–MS/MS-based metabolite profiling identified elevated levels of p-coumaroyl hexose, caffeic acid hexoside and ferulic acid hexoside in CCR-RNAi lines,(More)
Cell wall fluorescence and immunocytochemistry demonstrate that xylem parenchyma cell walls do not show changes in structure and composition related to gravitropic response comparable to those of tracheids, even when they have lignified secondary cell walls. Tracheid cell walls in compression wood have altered composition and structure which generates the(More)
Young P. omorika trees subjected to static bending showed a severe compression wood response as characterized by fluorescence spectroscopy/microscopy, which decreased in severity with height correlated with a decrease in bending moment. This investigation is aimed at understanding the reaction wood response in a slow-growing conifer species under conditions(More)
The design, construction and application of a Pinus microarray platform are described. The oligonucleotide microarray was developed using publicly available Pinus cDNA sequences mostly derived from Pinus taeda to test whether heterologous hybridisation of microarray probes will generate useful data when hybridised with cRNA constructed from the dominant New(More)
Tissue culture has been viewed as a relatively safe method of transporting conifer germplasm as the risk of pathogens associated with tissue cultured material has been assumed to be low. Despite these assumptions, it is unknown whether tissue cultured propagation material contains microorganisms or whether such microorganisms could grow out onto the media(More)
Mapping the location of bound cellulase enzymes provides information on the micro-scale distribution of amenable and recalcitrant sites in pretreated woody biomass for biofuel applications. The interaction of a fluorescently labelled cellulase enzyme cocktail with steam-exploded pine (SEW) was quantified using confocal microscopy. The spatial distribution(More)
A technique whereby whole mounts of delicate tissues of differentiating xylem are imaged directly by polishing and block-face imaging of embedded microcores. Autofluorescence and image analysis aids identifying the stages of xylogenesis. Stem microcores from fast-growing trees, such as Pinus radiata (D. Don) with wide zones of cambium and differentiating(More)