WOX11 and 12 Are Involved in the First-Step Cell Fate Transition during de Novo Root Organogenesis in Arabidopsis

De novo organogénesis is a process through which wounded or detached plant tissues or organs regenerate adventitious roots and shoots. Plant hormones play key roles in de novo organogenesis, whereas the mechanism by which hormonal actions result in the first-step cell fate transition in the whole process is unknown. Using leaf expiants oí Arabidopsis thaliana, we show that the homeobox genes WUSCHEL RELATED H0MEOBOX11 (WOX11) and WOX12 are involved in de novo root organogénesis. WOX11 directly responds to a wounding-induced auxin maximum in and surrounding the procambium and acts redundantly with its homolog WOX12 to upregulate LATERAL ORGAN BOUNDARIES DOMAIN 16 (LBD16) and LBD29, resulting in the first-step cell fate transition from a leaf procambium or its nearby parenchyma cell to a root founder cell. In addition, our results suggest that de novo root organogénesis and callus formation share a similar mechanism at initiation.