Characterization of Potato Gain-of-Function
Insertional Mutants

A novel resource created by the Canadian Potato Genome Project is a large collection of activation tagged lines derived from the potato cultivar Bintje. T-DNA activation tagging is a useful method to generate dominant mutations in plants or plant cells, by transformation with T-DNA carrying constitutive enhancer elements (Weigel et al., 2000; Mathews et al., 2003). The dominant character of the mutation, caused by transcriptional activation of flanking plant genes, has proven suitable for the isolation of genes regulating complex developmental and metabolic pathways.

At present, 8613 activation tagged mutant potato lines have been created, but with minimal characterization. This collection is already the largest publicly known collection of mutant lines of potatoes in the world, and promises to be a vital resource in gene discovery for potatoes, as well as other tuber-bearing crops. Activation tagging has been an effective means to identify functional mutations in Solanaceae species.

Screening of these lines for phenotypic traits has started, and we are concentrating on several lines with modified tuber qualities relating to reducing sugar levels and specific gravity.