Maize NCP1 negatively regulates drought and ABA responses through interacting with and inhibiting the activity of transcription factor ABP9.
Plant Mol Biol
; 102(3): 339-357, 2020 Feb.
Article
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| MEDLINE
| ID: mdl-31894455
ABSTRACT
KEY MESSAGE NCP1, a NINJA family protein lacking EAR motif, acts as a negative regulator of ABA signaling by interacting with and inhibiting the activity of transcriptional activator ABP9. The phytohormone abscisic acid plays a pivotal role in regulating plant responses to a variety of abiotic stresses including drought and salinity. Maize ABP9 is an ABRE-binding bZIP transcription activator that enhances plant tolerance to multiple stresses by positively regulating ABA signaling, but the molecular mechanism by which ABP9 is regulated in mediating ABA responses remains unknown. Here, we report the identification of an ABP9-interacting protein, named ABP Nine Complex Protein 1 (NCP1) and its functional characterization. NCP1 belongs to the recently identified NINJA family proteins, but lacks the conserved EAR motif, which is a hallmark of this class of transcriptional repressors. In vitro and in vivo assays confirmed that NCP1 physically interacts with ABP9 and that they are co-localized in the nucleus. In addition, NCP1 and ABP9 are similarly induced with similar patterns by ABA treatment and osmotic stress. Interestingly, NCP1 over-expressing Arabidopsis plants exhibited a reduced sensitivity to ABA and decreased drought tolerance. Transient assay in maize protoplasts showed that NCP1 inhibits the activity of ABP9 in activating ABRE-mediated reporter gene expression, a notion further supported by genetic analysis of drought and ABA responses in the transgenic plants over-expressing both ABP9 and NCP1. These data together suggest that NCP1 is a novel negative regulator of ABA signaling via interacting with and inhibiting the activity of ABP9.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Reguladores del Crecimiento de las Plantas
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Proteínas de Plantas
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Factores de Transcripción
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Transducción de Señal
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Zea mays
/
Sequías
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Plant Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2020
Tipo del documento:
Article