http://cfs.nrcan.gc.ca/authors/read/14577?format=title Publications by T.A. Holmes en-ca 2009-03-10 00:00:00 MST 2009-03-10 00:00:00 MST webmaster@nofc.cfs.nrcan.gc.ca http://cfs.nrcan.gc.ca/publications?id=29356 Interactions between roots of Douglas-fir (DF; Pseudotsuga menziesii) seedlings and the laminated root rot fungus Phellinus sulphurascens were investigated using scanning and transmission electron microscopy and immunogold labelling techniques. Scanning electron micrographs revealed that P. sulphurascens hyphae colonize root surfaces and initiate the penetration of root epidermal tissues by developing appressoria within 2 d postinoculation (dpi). During early colonization, intra- and intercellular fungal hyphae were detected. They efficiently disintegrate cellular components of the host including cell walls and membranes. P. sulphurascens hyphae penetrate host cell walls by forming narrow hyphal tips and a variety of haustoria-like structures which may play important roles in pathogenic interactions. Ovomucoid-WGA (wheat germ agglutinin) conjugated gold particles (10 nm) confirmed the occurrence and location of P. sulphurascens hyphae, while four specific host pathogenesis-related (PR) protein antibodies conjugated with protein A-gold complex (20 nm) showed the localization and abundance of these PR proteins in infected root tissues. A thaumatin-like protein and an endochitinase-like protein were both strongly evident and localized in host cell membranes. A DF-PR10 protein was localized in the cell walls and cytoplasm of host cells while an antimicrobial peptide occurred in host cell walls. A close association of some PR proteins with P. sulphurascens hyphae suggests their potential antifungal activities in DF roots. Tue, 10 Mar 2009 http://cfs.nrcan.gc.ca/publications?id=29356 http://cfs.nrcan.gc.ca/publications?id=3243 In this report, microscopical techniques, including transmission and scanning electron microscopy, light and fluorescence microscopy, and immunocytochemistry are reviewed with examples from recent literature to illustrate prospective forestry applications. The purpose of this report is to explore potential applications of microtechniques to forest research programs in areas such as pathogen and insect management, biorational forest weed control, ecosystem dynamics, and seed and nursery research. Also included is a table of equipment currently available in the microtechnique laboratory at the Pacific Forestry Centre. Recent technical innovations and the future prospects of these techniques are discussed. Sat, 26 Aug 2000 http://cfs.nrcan.gc.ca/publications?id=3243