While gibberellin (GA) and abscisic acid (ABA) responses are an essential factor in plant growth, development, and adaptation to the environment, it remains unclear how these hormones move in the plant, where they accumulate, and what is the physiological relevance of such accumulation.
In a study published in the journal Nature Plants, scientists from the Patrick Achard‘s group at the Institute of Molecular Biology of Plants (IBMP) in collaboration with 9 international teams, identified and characterized NPF2.12, NPF2.13 and NPF2.14, three closely related GA and ABA transporters. NPF2.12 and NPF2.13 are two plasma membrane-localized importers required for GA12 loading (the major long-distance GA signaling form) into the phloem and its translocation from shoots to roots. NPF2.14 is a sub-cellular exporter localized in the membrane of pericycle vacuole, which serves as a storage source for both hormones. Using multi-disciplinary approaches, the authors of the study demonstrate that these transporters are essential for GA and ABA accumulation in the endodermis and for the formation of suberin in the root maturation zone.