Immunogold labelling of size marker proteins in brown rot-degraded pine wood
IRG/WP 1428
E Srebotnik, K Messner
Pine wood degraded by Fomitopsis pinicola was infiltrated with a mixture of ovalbumin (45 kDa) and myoglobin (16.7 kDa). After crosslinking of the proteins with glutaraldehyde and preparation for electron microscopy ultrathin sections were labeled with gold-conjugated antibodies. Simultaneous labeling of both proteins on the same section showed that at 50-70% weight loss ovalbumin did not penetrate the brown rot-degraded wood cell walls at all, while partial penetration was observed with myoglobin. Considerable areas of the wood cell walls were not penetrated even by the small myoglobin molecules, although extensive degradation was evident. The results suggest that not only the initial brown rot attack, but all chemical reactions taking place inside the wood cell walls, depolymerization of cellulose to soluble oligosaccharides as well as lignin modification, are caused by a low molecular weight fungal agent.