Project Number: 3655-21000-049-25
Project Type: Specific Cooperative Agreement

Start Date: Jul 21, 2011
End Date: Jul 31, 2013

Objective:
(1) Develop lines of potato cultivar Atlantic in which the genes for aparagine synthetase (ASy) and vacuolar acid invertase (VInv) are suppressed. (2) Quantify asparagine and reducing sugars in cold-stored tubers of these lines. (3) Measure acrylamide in potato chips made from these lines and relate to asparagine and reducing sugar content in raw tubers. (4) Evaluate the growth of suppressed lines and identify potential agronomic problems.

Approach:
Develop silenced lines: The RNA interference (RNAi) approach will be used for potato gene silencing. We will transform our existing lines of Atlantic that have strong suppression of the VInv gene with silencing constructs that target the two potato ASy genes (2). These lines will be characterized with regard to expression of the three silenced genes. Individuals with a range of ASy gene silencing will be selected for detailed analysis. Biochemical characterization of tubers: Tuber sucrose, glucose and fructose contents will be quantified by HPLC. Tuber asparagine content will be measured with the L-asparagine/L-glutamine assay kit (Megazyme). Acrylamide content of fried chips will be measured in the Department of Bacteriology, UW Madison. Evaluation of plant growth: Transformed lines will be grown in greenhouses using standard procedures to produce tubers for biochemical analysis. Growth characteristics of plants and tuber number, weight and shape will be documented for each line and for Atlantic controls. Differences between controls and silenced lines may indicate potential limits on agronomic performance that will be investigated further in subsequent years.