Wound response and primary metabolism during adventitious root formation in cuttings

Abstract

The formation of adventitious roots (ARs) is primarily considered as a most crucial developmental phase for the vegetative propagation of plants. AR either originates naturally in whole plants, as a programmed developmental process, or develops in response to any stress or injury, for example, in cuttings. AR formation in plants is a complex and multistep process, regulated by several factors such as environmental stimuli and endogenous hormones. Availability of energy sources and supply of nitrogen and amino acid affect the pace and intensity of AR formation. Furthermore, significant alterations in enzyme activities and metabolite accumulation observed in plant cuttings suggest that the activity of specific enzymes and metabolites governs AR formation. Profiling of metabolites displays a significant increase in organic acids and several essential amino acids. There are major metabolic stages in AR formation: (1) sink establishment phase, (2) recovery phase, and (3) maintenance phase. However, available information regarding the molecular and physiological basis of AR formation is scarce and requires further investigations to unfold the precise mechanism of AR formation. Therefore, the present article is an attempt to provide a better understanding of AR formation in plant cuttings. Furthermore, the focus is also given to equate the corelation between varied actions of the aforementioned factors during AR formation.