Review. Auxin canalization: From speculative models toward molecular players (Curr Opin Plant Biol)

The versatility of roles that the hormone auxin plays led Paque and Weijers to suggest a new meaning to the acronym IAA (originally- Indole Acetic Acid)- ‘Influences Almost Anything’. It is known that PIN-FORMED (PIN) auxin exporters are responsible for cell-to-cell directional auxin flow and auxin induces the co-ordination and polarization of PINs. In their recent review article, authors Hajný, Tan and Friml addresses with some long-standing questions and puts forth some interesting hypothesis regarding the mechanism of auxin canalization. For example, the authors hypothesize that the auxin flowing through the cell and the cell sensing the neighbor with the lowest auxin level determine the positioning of PIN proteins and formation of the canal. Additionally, they say that sub-cellular dynamics of PIN and actin and myosin functions are also required for auxin canalization during vasculature formation and regeneration after wounding. This opinion article is a must-read for every plant biologist. (Summary by Sibaji K Sanyal @SibajiSanyal) Curr. Opin. Plant Biol. 10.1016/j.pbi.2022.102174