De novo root regeneration from leaf explants: wounding, auxin, and cell fate transition.

Root organogenesis after tissue damage is a type of plant regeneration known as de novo root regeneration (DNRR). The DNRR process is widely exploited in agricultural technologies, such as cuttings for vegetative propagation. This review summarizes recent advances in our understanding of the cellular and molecular framework of DNRR, mainly focusing on rooting from Arabidopsis thaliana leaf explants. The framework comprises three successive phases, that is, early signaling, auxin accumulation, and cell fate transition, and involves two types of cells with different functions: the converter cell that converts the early signals as the input into auxin flux as the output; and the regeneration-competent cell that undergoes fate transition guided by auxin.