Role of cell wall structure in soft rot decay of bamboo
O Sulaiman, R J Murphy
Models of soft rot hyphal penetration of bamboo cell walls are proposed. Soft rot hyphae show an interesting capability of penetrating the bamboo cell wall in different forms; typical longitudinal penetrating hyphae and tangentially orientated penetrating hyphae. The second form of penetration was found to be different from that normally associated with wood cell walls. The differences can be attributed to the cell wall structure of bamboo. Soft rot hyphae normally follow the microfibrillar orientation in either the broad lamellae or the narrow lamellae in bamboo cell walls. Hyphae that grow in the broad lamellae normally penetrate in the longitudinal direction and follow the orientation of the microfibrils of this layer of the cell wall. This produces a 'typical' longitudinal penetrating hyphae and cavity. Soft rot hyphae are also found penetrating in the tangential direction. These arise from radially orientated hyphae trying to penetrate across the lamellated cell wall neighbouring cells. When a radially orientated hyphae encounters the narrow lamellae, the hyphae can reorientate in the direction of the microfibrils in this lamellae. Thus, the hyphae penetrate in a tangential direction in the cell wall. These types of penetrations are not seen in wood cell walls.