A Tonoplast-Associated Calcium-Signaling Module Dampens ABA Signaling during Stomatal Movement.
Plant Physiol
; 177(4): 1666-1678, 2018 08.
Article
en En
| MEDLINE
| ID: mdl-29898977
ABSTRACT
Stomatal movement, critical for photobiosynthesis, respiration, and stress responses, is regulated by many factors, among which abscisic acid (ABA) is critical. Early events of ABA signaling involve Ca2+ influx and an increase of cytoplasmic calcium ([Ca2+]cyt). Positive regulators of this process have been extensively studied, whereas negative regulators are obscure. ABA-induced stomatal closure involves K+ flux and vacuolar convolution. How these processes are connected with Ca2+ is not fully understood. We report that pat10-1, a null mutant of Arabidopsis (Arabidopsis thaliana) PROTEIN S-ACYL TRANSFERASE10 (PAT10), is hypersensitive to ABA-induced stomatal closure and vacuolar convolution. A similar phenotype was observed in cbl2;cbl3, the double mutant of CBL2 and CBL3, whose tonoplast association depends on PAT10. Functional loss of the PAT10-CBL2/CBL3 system resulted in enhanced Ca2+ influx and [Ca2+]cyt elevation. Promoting vacuolar K+ accumulation by overexpressing NHX2 suppressed ABA-hypersensitive stomatal closure and vacuolar convolution of the mutants, suggesting that PAT10-CBL2/CBL3 positively mediates vacuolar K+ accumulation. We have identified CBL-interacting protein kinases (CIPKs) that mediate CBL2/CBL3 signaling during ABA-induced stomatal movement. Functional loss of the PAT10-CBL2/3-CIPK9/17 system in guard cells enhanced drought tolerance. We propose that the tonoplast CBL-CIPK complexes form a signaling module that negatively regulates ABA signaling during stomatal movement.
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MEDLINE
Asunto principal:
Arabidopsis
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Ácido Abscísico
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Señalización del Calcio
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Estomas de Plantas
Tipo de estudio:
Prognostic_studies
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Risk_factors_studies
Idioma:
En
Año:
2018
Tipo del documento:
Article