Gibberellin and abscisic acid transporters facilitate endodermal suberin formation in Arabidopsis

The plant hormone gibberellin (GA) regulates multiple developmental processes. It accumulates in the root elongating endodermis, but how it moves into this cell file and the significance of this accumulation are unclear. Here, we identified a monophyletic clade of NPF transporters required for GA and abscisic acid (ABA) translocation. We demonstrate that NPF2.14 is a subcellular GA/ABA transporter, the first to be identified in plants, facilitating GA and ABA accumulation in the root endodermis to regulate suberization. Further, NPF2.12 and NPF2.13, closely related proteins, are plasma membrane-localized GA and ABA importers that facilitate shoot-to-root GA₁₂ translocation, regulating endodermal hormone accumulation. This work reveal that GA promotes root suberization and that GA and ABA can act non-antagonistically. We demonstrated how a clade of transporters mediates hormone flow while utilizing defined cell-file-specific vacuolar storage at the phloem unloading zone, allowing a hormone slow-release mechanism required for suberin formation in the maturation zone.