The aim of this project was to study starch phosphorylase gene expression in potato tubers during different physiological conditions when starch was mobilised, like wound healing and sprouting. One of the objectives was to clone plastidic potato tuber starch phosphorylase cDNA. cDNA libraries were constructed using mRNA from wounded and unwounded tuber tissue as templates for cDNA synthesis. Based on the amino acid sequence (Nakano & Fukui, 1986) of specific regions of potato tuber starch phosphorylase, two different sets of mixed oligonucleotide probes (called SP1 and SP2) were prepared and subsequently used to screen the cDNA libraries for starch phosphorylase recombinants
