Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

Identification Of Differentially Expressed ESTs During Potato Storage And Their Relationship To After-Cooking Darkening

Gefu Wang-Pruski¹ , Rebecca Griffiths² , Martin Lagüe³ , David DeKoeyer³ , Charlotte Rothwell² , Vicki Gustafson² , Barry Flinn⁴ , Sharon Regan⁵

¹  Nova Scotia Agricultural College, Department of Plant and Animal Sciences, 50 Pictou Road, Truro, Nova Scotia, B2N 5E3, Canada

²  Genome Atlantic, 921 College Hill Road, Fredericton, New Brunswick, E3B 6Z9, Canada

³  AAFC, Potato Research Centre, 850 Lincoln Road, Fredericton, New Brunswick, E3B 9H8, Canada

⁴  Institute for Sustainable and Renewable Resources, 150 Slayton Ave., Danville, VA, USA 24540

⁵  Queen’s University, Department of Biology, Kingston, ON, K7L 3N6, Canada

After-cooking darkening, one of the most undesirable quality traits in potato (Solanum tuberosum L.), occurs in every potato growing area in the world. After-cooking darkening is a gray-black discoloration of the potato tuber that is formed after cooking as a result of the oxidation of a ferric-chlorogenic acid complex. The trait has a negative effect on the marketability of both table stock and processed potatoes. Currently, the processing industry controls the darkening by using iron-sequestering agents. After-cooking darkening is a complex trait, mainly genetically determined, but also influenced by field and storage conditions. As cold storage temperature and length are the major environmental factors influencing the severity of the darkening, cDNA libraries from tuber samples treated by storage conditions have been constructed as a part of the Canadian Potato Genome Project (www.cpgp.ca) potato gene discovery endeavour. The Canadian Potato Genome Project has generated ESTs from a wide range of potato cDNA libraries targeting on additional resources and knowledge towards an understanding of potato development, responses to storage and pathogen stresses. To do so, a combination of standard and normalized cDNA libraries have been developed and sequenced. Two libraries representing tuber post-harvest cold storage have been analyzed for genes that are uniquely presented in the treated samples. This presentation will demonstrate the number of unigenes that are identified and the functional annotations that reveal the predominant biological processes represented in each library. These data will provide essential information about storage effect on the degree of ACD in potatoes.