“…This positive feedback between auxin signaling and transport directionality is the key pre-requisite of the so-called auxin canalization (Sachs, 1981). The auxin canalization hypothesis proposes a mechanism for unique, self-organizing aspects of plant development such as the establishment of the apical/basal body axis during embryogenesis (Robert et al, 2013(Robert et al, , 2018, flexible formation of vascular strands during organ formation (Benková et al, 2003;Heisler et al, 2005;Bhatia et al, 2016), shoot branching (Bennett et al, 2014;, leaf venation (Scarpella et al, 2006;Govindaraju et al, 2020), vasculature regeneration after wounding (Sauer et al, 2006;Mazur et al, 2016Mazur et al, , 2020aHajný et al, 2020) and shoot gravitropic bending termination (Rakusová et al, 2016(Rakusová et al, , 2019Han et al, 2020). During canalization, auxin triggers coordinated PIN polarization to gradually establish directional auxin transport channels between auxin source and sink (Wabnik et al, 2010(Wabnik et al, , 2011Prát et al, 2018).…”