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Research article - Peer-reviewed, 2019

Cellular level chemical changes in Scots pine heartwood during incipient brown rot decay

Belt, Tiina; Altgen, Michael; Makela, Mikko; Hanninen, Tuomas; Rautkari, Lauri


The heartwoods of many wood species have natural resistance to wood decay due to the accumulation of antifungal heartwood extractives. The natural durability of heartwoods has been extensively investigated, yet very little information is available on the initiation of heartwood decay. This experiment examined the onset of Rhodonia placenta brown rot decay in Scots pine heartwood in order to identify the key changes leading to heartwood decay. An imaging approach based on Raman imaging and multivariate image analysis revealed that the degradation of heartwood began in the innermost cell wall layers and then spread into the remaining cell walls and the middle lamella. Pinosylvins were extensively degraded in the cell walls, middle lamella and extractive deposits, while unidentified material most likely consisting of hemicelluloses and/or lipophilic extractives was removed from the inner cell wall layers. Changes similar to inner cell wall degradation were seen in the remaining cell walls in more advanced decay. The results indicate that the key change in incipient heartwood decay is the degradation of antifungal heartwood extractives. The inner cell wall degradation seen in this experiment may serve a nutritive purpose or facilitate the penetration of degradative agents into the cell walls and middle lamella.

Published in

Scientific Reports
2019, volume: 9, article number: 5188

Authors' information

Belt, Tiina
Aalto University
Altgen, Michael
Aalto University
Aalto University
Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology
Hanninen, Tuomas
Aalto University
Rautkari, Lauri
Aalto University

UKÄ Subject classification

Forest Science

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