Genetic and molecular networks mediating potato tuber development

Potato, the world's third most important food crop, is cultivated world-wide for its tubers that store high-energy photoassimilates, which are predominantly induced under short photoperiods with cooler night temperatures. The stored photoassimilates ensure plant survival by vegetative propagation and to support subsequent shoot growth. The leaf-generated main tuberigen signal, StSP6A, upon its transport to stolon, forms tuber-inducing Tuberigen Activation Complex (TAC). Misregulation or redirection of StSP6A transport toward lateral buds contributes to aerial tuber formation, thereby adversely affecting underground tuber yield. The activity of TAC is inhibited by antituberigens, such as StAST1 and StTFL1, which compete with StSP6A and constitute anti-TAC. In this review, we provide a comprehensive overview of the genetic and molecular mechanisms underlying underground and aerial tuber formation, their regulation by antituberigen factors, key genes controlling stolon-to-tuber transitions, the role of StSWEET-StSUT transporters in establishing the source-sink relationship essential for tuber development, and the evolution and global dissemination of modern potato cultivars. Collectively, insights from potato provide a valuable framework for understanding the conserved and divergent mechanisms governing storage organ development in other economically important crops.