Two CCAAT-box-binding transcription factors redundantly regulate early steps of the legume-rhizobia endosymbiosis.
Plant J
; 79(5): 757-68, 2014 Sep.
Article
en En
| MEDLINE
| ID: mdl-24930743
ABSTRACT
During endosymbiotic interactions between legume plants and nitrogen-fixing rhizobia, successful root infection by bacteria and nodule organogenesis requires the perception and transduction of bacterial lipo-chitooligosaccharidic signal called Nod factor (NF). NF perception in legume roots leads to the activation of an early signaling pathway and of a set of symbiotic genes which is controlled by specific early transcription factors (TFs) including CYCLOPS/IPD3, NSP1, NSP2, ERN1 and NIN. In this study, we bring convincing evidence that the Medicago truncatula CCAAT-box-binding NF-YA1 TF, previously associated with later stages of rhizobial infection and nodule meristem formation is, together with its closest homolog NF-YA2, also an essential positive regulator of the NF-signaling pathway. Here we show that NF-YA1 and NF-YA2 are both expressed in epidermal cells responding to NFs and their knock-down by reverse genetic approaches severely affects the NF-induced expression of symbiotic genes and rhizobial infection. Further over-expression, transactivation and ChIP-PCR approaches indicate that NF-YA1 and NF-YA2 function, at least in part, via the direct activation of ERN1. We thus propose a model in which NF-YA1 and NF-YA2 appear as early symbiotic regulators acting downstream of DMI3 and NIN and possibly within the same regulatory complexes as NSP1/2 to directly activate the expression of ERN1.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Simbiosis
/
Transducción de Señal
/
Sinorhizobium meliloti
/
Regulación de la Expresión Génica de las Plantas
/
Factor de Unión a CCAAT
/
Medicago truncatula
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Francia