Adventitious Root Formation: New Insights and Perspectives

Abstract The root system of a plant consists of the primary, lateral and adventitious roots. Lateral roots always develop from roots whereas adventitious roots form from stem or leaf‐derived cells. Adventitious rooting is an essential step in the vegetative propagation of economically important horticultural and woody species. It allows clonal propagation and rapid fixation of superior genotypes prior to their introduction into production or breeding programs. Problems associated with rooting of cuttings frequently result in significant economic losses. Development of adventitious roots is a complex process that is affected by multiple factors including phytohormones, light, nutritional status, associated stress responses such as wounding, and genetic characteristics. How endogenous and environmental factors interact to control adventitious root formation is still poorly understood, although significant progress has been made in the understanding of the molecular control of root and lateral root development. In this review, we will summarize the current knowledge on the physiological aspects of AR formation and highlight the recent progress made in the identification of putative molecular players involved in the control of adventitious rooting.