Arabidopsis CPK6 positively regulates ABA signaling and drought tolerance through phosphorylating ABA-responsive element-binding factors.
J Exp Bot
; 71(1): 188-203, 2020 01 01.
Article
en En
| MEDLINE
| ID: mdl-31563949
ABSTRACT
Abscisic acid (ABA) regulates numerous developmental processes and drought tolerance in plants. Calcium-dependent protein kinases (CPKs) are important Ca2+ sensors playing crucial roles in plant growth and development as well as responses to stresses. However, the molecular mechanisms of many CPKs in ABA signaling and drought tolerance remain largely unknown. Here we combined protein interaction studies, and biochemical and genetic approaches to identify and characterize substrates that were phosphorylated by CPK6 and elucidated the mechanism that underlines the role of CPK6 in ABA signaling and drought tolerance. The expression of CPK6 is induced by ABA and dehydration. Two cpk6 T-DNA insertion mutants are insensitive to ABA during seed germination and root elongation of seedlings; in contrast, overexpression of CPK6 showed the opposite phenotype. Moreover, CPK6-overexpressing lines showed enhanced drought tolerance. CPK6 interacts with and phosphorylates a subset of core ABA signaling-related transcription factors, ABA-responsive element-binding factors (ABFs/AREBs), and enhances their transcriptional activities. The phosphorylation sites in ABF3 and ABI5 were also identified through MS and mutational analyses. Taken together, we present evidence that CPK6 mediates ABA signaling and drought tolerance through phosphorylating ABFs/AREBs. This work thus uncovers a rather conserved mechanism of calcium-dependent Ser/Thr kinases in ABA signaling.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Arabidopsis
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Proteínas Quinasas Dependientes de Calcio-Calmodulina
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Regulación de la Expresión Génica de las Plantas
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Proteínas de Arabidopsis
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Factores de Transcripción con Cremalleras de Leucina de Carácter Básico
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Exp Bot
Asunto de la revista:
BOTANICA
Año:
2020
Tipo del documento:
Article
País de afiliación:
China