Investigations of the regulation of anthocyanin side chain decoration in colored potatoes

Potato is among the most important staple foods worldwide. Pigmented varieties can provide a major quantitative source of anthocyanins which are considered to have health-promoting effects, linked to their antioxidant capacity (Prior 2003). This promotes an increasing interest in anthocyanin rich 'blue' potatoes as functional food from the food industry, nutritional science and consumers. Pigmented potatoes show a tremendous variability in anthocyanin content and in their specific composition and supply a suitable model system for investigation of anthocyanin side chain regulation in crops. In our studies we aim at investigation of regulatory mechanisms controlling side chain decoration of anthocyanins in potato. We selected 60 different varieties of cultivated anthocyanin pigmented potatoes from the Gross Luesewitz Potato Collections of the IPK Genebank (GLKS) to perform LC-MS based anthocyanin profile analysis of extracts from potato flesh and peel, respectively. Further assortment was due to interesting profiles showing only a few distinct peaks for anthocyanins different in side chain decoration. We will present results for the examination of anthocyanin composition including metabolite profiling and phytochemical characterization by means of an LC-MS based approach. Selected lines will be further monitored for their anthocyanin profiles during tuber development. Further studies will include comparative gene expression analysis in different developmental stages to analyze quantitative differences in anthocyanin biosynthesis key gene expression, validated also by enzyme expression analyses. Additionally, we will study promoter regulation. We will create RNAi lines to study promoter and gene function and the relevance of transcription factors for regulation of anthocyanin profiles.