Coloring Outside the Lines:Potato tuber skin and flesh color matter; do we know where it comes from?

摘要

One of the most important and eye-catching potato tuber traits is tuber color. Skin and flesh color are equally important for consumers in different countries and continents. Some people prefer red-skinned potatoes, while other eat nearly exclusivelyyellow-skinned varieties. There is an increasing importance placed in understanding tuber color formation in order to suppor breeding programs to establish modern varieties that meet consumers' requirements.The presence of anthocyanins in tuber skin and flesh can strongly influence their color and appearance. Additionally, anthocyanins and polyphenols accumulating in tubers are potent sources of antioxidants. Being bioactive compounds, they have potential health benefits. Anthocyanin accumulation is influenced by the balance between biosynthesis and degradation; a conserved network of activators and repressors were identified in several plant species. A common set of transcription factors including MYB, MYC and WD40 family members were described previously. In 1955, research proved that in diploid potato, three genetic loci—P, R and I—describe anthocyanin accumulation in tuber skin. Later, these genes were identified by Walter De Jong, a potato breederat Cornell University, and other scientists. Anthocyanin development is a complex process, and not everything could be explained by the identified factors. Diploid and tetraploid potatoes have an incredible variation in primary and secondary skin color and distribution. Also, tuber flesh pigmentation varies well among cultivars. Recently, MYB transcription factors have come into prominence and widened our knowledge about anthocyanin production.