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Research article2015Peer reviewed

Ultrastructure and immunocytochemistry of degradation in spruce and ash sapwood by the brown rot fungus Postia placenta: Characterization of incipient stages of decay and variation in decay process

Kim, Jong Sik; Gao, Jie; Daniel, Geoffrey

Abstract

Aspects of the degradation of non-cellulosic polysaccharides (pectins, hemicelluloses) in spruce and ash sapwood by the brown rot fungus Postia placenta was investigated using transmission electron microscopy coupled with immunocytochemistry. Degradation of non-cellulosic polysaccharides and changes in ultrastructure were initiated in the compound middle lamella (CML)/middle lamella cell corner (MLcc) regions of xylem cells; sites that were remote from hyphal colonization in the cell lumen. Degradation of the S-3 layer was also detected in both wood species at early stages of decay. Apart from early stages of attack, the degradation patterns differed greatly between spruce and ash. Spruce showed three patterns of hemicellulose degradation in the secondary cell walls of tracheids, while ash showed a single pattern in fibers. Spruce parenchyma cells also showed lower resistance to decay than tracheids, whereas ash parenchyma. cells showed higher resistance than fibers. Together, degradation of xylem cells by P. placenta differs between spruce (softwood) and ash (hardwood) even though they show similar initial degradation in CML/MLcc regions and the S-3 layer. The overall degradation patterns observed, particularly in spruce differ from previous ideas and generally accepted decay patterns produced by brown rot fungi in wood. (C) 2015 Elsevier Ltd. All rights reserved.

Keywords

Brown rot decay; Middle lamella decay; Immunocytochemistry; Hemicellulose; Pectin; Postia placenta

Published in

International Biodeterioration and Biodegradation
2015, Volume: 103, pages: 161-178

      SLU Authors

    • Kim, Jongsik

      • Department of Forest Products, Swedish University of Agricultural Sciences

      • Gao, Jie

        • Department of Forest Products, Swedish University of Agricultural Sciences

        • Daniel, Geoffrey

          • Department of Forest Products, Swedish University of Agricultural Sciences

        Associated SLU-program

        SLU Plant Protection Network

        UKÄ Subject classification

        Wood Science
        Forest Science

        Publication identifier

        DOI: https://doi.org/10.1016/j.ibiod.2015.05.005

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/69742