A Molecular Framework for the Control of Adventitious Rooting by TIR1/AFB2-Aux/IAA-Dependent Auxin Signaling in Arabidopsis.
Mol Plant
; 12(11): 1499-1514, 2019 11 04.
Article
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| MEDLINE
| ID: mdl-31520787
ABSTRACT
In Arabidopsis thaliana, canonical auxin-dependent gene regulation is mediated by 23 transcription factors from the AUXIN RESPONSE FACTOR (ARF) family that interact with auxin/indole acetic acid repressors (Aux/IAAs), which themselves form co-receptor complexes with one of six TRANSPORT INHIBITOR1/AUXIN-SIGNALLING F-BOX (TIR1/AFB) proteins. Different combinations of co-receptors drive specific sensing outputs, allowing auxin to control a myriad of processes. ARF6 and ARF8 are positive regulators of adventitious root initiation upstream of jasmonate, but the exact auxin co-receptor complexes controlling the transcriptional activity of these proteins has remained unknown. Here, using loss-of-function mutants we show that three Aux/IAA genes, IAA6, IAA9, and IAA17, act additively in the control of adventitious root (AR) initiation. These three IAA proteins interact with ARF6 and/or ARF8 and likely repress their activity in AR development. We show that TIR1 and AFB2 are positive regulators of AR formation and TIR1 plays a dual role in the control of jasmonic acid (JA) biosynthesis and conjugation, as several JA biosynthesis genes are up-regulated in the tir1-1 mutant. These results lead us to propose that in the presence of auxin, TIR1 and AFB2 form specific sensing complexes with IAA6, IAA9, and/or IAA17 to modulate JA homeostasis and control AR initiation.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Transducción de Señal
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Arabidopsis
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Receptores de Superficie Celular
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Raíces de Plantas
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Proteínas de Arabidopsis
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Proteínas F-Box
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Ácidos Indolacéticos
Idioma:
En
Revista:
Mol Plant
Asunto de la revista:
BIOLOGIA MOLECULAR
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BOTANICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Suecia