ARS | Publication request: CHANGES IN CELL WALL PECTIN ASSOCIATED WITH PERIDERM MATURATION IN POTATO TUBER

Submitted to: Abstract of International Horticultural Congress
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2001
Publication Date: N/A

Technical Abstract: Potato (Solanum tuberosum L.) periderm maturation is an important physiological process that reduces tuber susceptibility to skinning injury. Skinning of potato tubers results in millions of dollars of losses to producers in the United States every year. Maturation of tuber periderm is often incomplete at harvest and renders the tuber susceptible to skinning injury. A skinned tuber is vulnerable to dehydration and infection during storage until it develops a wound periderm to replace the damaged native periderm. Both native and wound periderms consist of three different cell types: phellem, phellogen, and phelloderm. The phellem and phelloderm are derived from the merstematic phellogen layer. We have recently determined that changes in the architecture of the phellogen cell walls upon periderm maturation are directly associated with development of resistance to skinning injury. The radial walls of phellogen cells are thin and labile to ofracture in immature periderm, but thicken and become resistant to fractur upon maturation of the periderm. Our research indicates that an increase in un-esterified pectins in phellogen cell walls accompanies maturation of the native periderm. Immunolocalization of both methyl-esterified and un- esterified pectin in native and wound periderm will be discussed. These results are important in identifying the biochemical processes responsible for periderm maturation and resistance to tuber skinning.