Gibberellin and abscisic acid transporters facilitate endodermal suberin formation in Arabidopsis

Abstract

The plant hormone gibberellin (GA) regulates multiple developmental processes. It accumulates in the root elongating endodermis, but how it moves into this cell le and the signi cance of this accumulation are unclear. Here, we identi ed 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 rst to be identi ed 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 GA 12 translocation, regulating endodermal hormone accumulation. This work reveal that GA promotes root suberization and that GA and ABA can act nonantagonistically. We demonstrated how a clade of transporters mediates hormone ow while utilizing de ned cell-le-speci c vacuolar storage at the phloem unloading zone, allowing a hormone slow-release mechanism required for suberin formation in the maturation zone.

Red light perception by the root is essential for gibberellin-induced primary-root elongation in tomato

“…The degradation of DELLA by GA in dark-grown roots releases these TFs and probably triggers transcriptional activation of numerous pathways independently of light. These may include the regulation of root architecture (Castro-Camba et al ., 2022), secondary xylem development, lignification (Wang et al, 2017) and endodermal suberin formation (Binenbaum et al ., 2023), but not cell elongation. Several DELLA-interacting TFs are involved in GA regulation of cell elongation (de Lucas et al ., 2008; Feng et al ., 2008; Gallego-Bartolome et al ., 2012; Chaiwanon & Wang, 2015).…”

Highlights in gibberellin research: A tale of the dwarf and the slender

“…It was furthermore demonstrated that GA 12 derived in the roots plays a role in regulating the growth of shoots in response to temperature changes in Arabidopsis ( Camut et al 2019 ). Most recently, it was reported that two GA and ABA transporters (NPF2.12 and NPF2.13) are required for shoot-to-root GA 12 translocation to regulate endodermal root suberization (summarized below) ( Binenbaum et al 2023 ).…”

“…Recent research has revealed that a subset of NPF proteins is required for the mechanisms behind long-distance GA transport from shoot to root and its developmental importance ( Binenbaum et al 2023 ). GA transport plays a critical role in suberin formation in the root.…”

“…GA transport plays a critical role in suberin formation in the root. NPF2.12 and NPF2.13 (2 recently identified GA and ABA importers), along with NPF2.14 (a tonoplast importer), coordinate the regulation of suberin formation ( Binenbaum et al 2023 ). NPF2.12 and NPF2.13 are membrane-localized proteins expressed in leaf phloem companion cells that facilitate the transport of GA 12 from shoot to root ( Fig.…”

Ascorbic acid releases dormancy and promotes germination by an integrated regulation of abscisic acid and gibberellin in Pyrus betulifolia seeds

“…Jang et al (2023) illustrated that the ABA and GA balance is not an absolute factor in determining dormancy. Binenbaum et al (2023) revealed that GA is required for root suberization and that GA and ABA can act non‐antagonistically. However, ABA positively regulates dormancy induction and maintenance, while GA alleviates dormancy and promotes seed germination (Tuan et al 2018; Barreto et al 2020).…”