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
em 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.
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1
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
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Arabidopsis
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Proteínas Quinases Dependentes de Cálcio-Calmodulina
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Regulação da Expressão Gênica de Plantas
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Proteínas de Arabidopsis
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Fatores de Transcrição de Zíper de Leucina Básica
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article