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.

Control of adventitious root formation: insights into synergistic and antagonistic hormonal interactions

“…Third, primordia emergence and outgrowth. ARI may occur in various cell types, with distinct anatomical and molecular identities, depending on both the species and environmental stimuli involved (reviewed by Geiss et al ). In Arabidopsis thaliana (Arabidopsis), ARs may be initiated from xylem pole pericycle cells in both intact and de‐rooted hypocotyls (Sorin et al , Sukumar et al ).…”

The auxin receptor TIR1 homolog (PagFBL 1) regulates adventitious rooting through interactions with Aux/IAA28 in Populus

“…The biological processes involved in AR formation are complex, and the temporal phases can be described as induction, initiation, activation of root primordium and out‐growth (Legué et al ., ). These processes are influenced by multiple factors, such as the genetic background and the physiological status of the mother plants, the application of hormones and environmental conditions (Geiss et al ., ; Pacurar et al ., ).…”

High miR156 Expression Is Required for Auxin-Induced Adventitious Root Formation via MxSPL26 Independent of PINs and ARFs in Malus xiaojinensis

“…Adventitious root formation depends on multiple factors, such as genetic background, developmental stage, hormones, and other internal and external cues (Geiss et al, 2009; da Costa et al, 2013). In most tree species, the ability to form adventitious roots decreases during the transition from juvenile to adult development phases.…”