The role of gibberellins in the control of tuberization in potato (Solanum tuberosum L.)

Abstract

Potato (Solanum tuberosum L.) is grown all over the world, being the fourth most important food crop after corn, rice and wheat. Potato tuber is formed from an underground stem, called stolon, whose tip swells to form the tuber under inducing conditions. This is a complex process that is influenced by many environmental factors, such as nitrogen level, light and temperature. Tuber development regulation is mediated by hormonal control mainly by gibberellic acid (GA, gibberellins), which plays a central role as negative regulator of the process. GA promotes stolon elongation and inhibits stolon swelling, diminishing tuber formation. Bioactive GA levels decline during tuber induction in stolons due to a complex transcriptional regulation of the GA metabolism genes. This chapter is focused on the mechanisms involved in the control of tuberization by GA, including the regulation of bioactive GA levels, the mechanism of action during tuber formation, and the interaction between GA and other hormones affecting tuberization.