Physiological and Molecular Mechanisms Associated with Potato Tuber Dormancy

Abstract

Tuber dormancy is an important physiological trait that impacts postharvest storage and end use qualities of potatoes. Overall, dormancy regulation of potato tuber is a complex process driven by genetic as well as environmental factors. Elucidation of the molecular and physiological mechanisms that influence different dormancy stages of tuber has wider potato breeding and industry relevant implications. Therefore, the primary objective of this review is to present the current knowledge on the diversity in tuber dormancy traits among wild relatives of potatoes and discuss how genetic and epigenetic factors contribute to the tuber dormancy. Advancements in understanding of key physiological mechanisms involved in tuber dormancy regulations, such as apical dominance, phytohormone metabolism, and oxidative stress responses were also discussed. This review highlights the impacts of common sprout suppressors on the molecular and physiological mechanisms associated with tuber dormancy and other storage qualities. Collectively, the literature suggests that significant changes in expressions of genes associated with cell cycle, phytohormone metabolism, and oxidative stress response influence initiation, maintenance, and termination of dormancy in potato tubers. Commercial sprout suppressors mainly alter the expressions of genes associated with cell cycle and stress responses and suppress sprout growth rather than prolonging the tuber dormancy.

Keywords: Apical dominance; Epigenetics; Gene regulation; Landraces; Oxidative stress; Physiological aging; Phytohormones; Sprout suppressor.