Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2000
Publication Date: N/A
Technical Abstract: Potato (Solanum tuberosum L.) periderm maturation is an important physiological process that reduces tuber susceptibility to skinning injury. This resistance to wounding protects the tuber from dehydration and infection after harvest. The periderm consists of three different cell types: phellem, phellogen, and phelloderm. We have recently determined that changes in the chemistry of phellogen cell walls are most closely associated with maturation of the native periderm and development of resistance to skinning injury. Immature tubers have phellogen cells with thin radial walls that fracture easily during handling. This wall fracturing is the primary cause of skinning injury. The development and maturation of a wound periderm which protects damaged tubers from infection shares many similarities with native periderm development and maturation. These similarities includes the differentiation of cells under the wound surface into phellogen cells. Recent results indicate that the development and maturation of wound periderm provides a useful model system to study the biochemical processes associated with susceptibility to skinning injury. Maturation of both native and wound periderm is accompanied by a reduction in the methylation of pectins in the walls of phellogen cells, as determined by histochemical staining and immunological labeling techniques. Reduction in pectin methylation may allow for the stabilization of these walls via calcium pectate formation. These results are important in identifying the biochemical processes responsible for periderm maturation and resistance to tuber skinning.