Publications

A secreted peptide acts on BIN2-mediated phosphorylation of ARFs to potentiate auxin response during lateral root development.

The phytohormone auxin is a key developmental signal in plants. So far, only auxin perception has been described to trigger the release of transcription factors termed AUXIN RESPONSE FACTORs (ARFs) from their AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) repressor proteins. Here, we show that phosphorylation of ARF7 and ARF19 by BRASSINOSTEROID-INSENSITIVE2 (BIN2) can also potentiate auxin signalling output during lateral root organogenesis. BIN2-mediated phosphorylation of ARF7 and ARF19 suppresses their interaction with AUX/IAAs, and subsequently enhances the transcriptional activity to their target genes LATERAL ORGAN BOUNDARIES-DOMAIN16 (LBD16) and LBD29. In this context, BIN2 is under the control of the TRACHEARY ELEMENT DIFFERENTIATION INHIBITORY FACTOR (TDIF)-TDIF RECEPTOR (TDR) module. TDIF-initiated TDR signalling directly acts on BIN2-mediated ARF phosphorylation, leading to the regulation of auxin signalling during lateral root development. In summary, this study delineates a TDIF-TDR-BIN2 signalling cascade that controls regulation of ARF and AUX/IAA interaction independent of auxin perception during lateral root development.

Cho, H., Ryu, H., Rho, S., Hill, K., Smith, S., Audenaert, D., Park, J., Han, S., Beeckman, T., Bennett, MJ., Hwang, D., De Smet, I. and Hwang, I. (2014) A secreted peptide acts on BIN2-mediated phosphorylation of ARFs to potentiate auxin response during lateral root development. . Nat. Cell Biol. 16. (abstract) (pmid) (doi)