THI1, a Thiamine Thiazole Synthase, Interacts with Ca2+-Dependent Protein Kinase CPK33 and Modulates the S-Type Anion Channels and Stomatal Closure in Arabidopsis.
Plant Physiol
; 170(2): 1090-104, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26662273
ABSTRACT
Thiamine is required for both plant growth and development. Here, the involvement of a thiamine thiazole synthase, THI1, has been demonstrated in both guard cell abscisic acid (ABA) signaling and the drought response in Arabidopsis (Arabidopsis thaliana). THI1 overexpressors proved to be more sensitive to ABA than the wild type with respect to both the activation of guard cell slow type anion channels and stomatal closure; this effectively reduced the rate of water loss from the plant and thereby enhanced its level of drought tolerance. A yeast two-hybrid strategy was used to screen a cDNA library from epidermal strips of leaves for THI1 regulatory factors, and identified CPK33, a Ca(2+)-dependent protein kinase, as interactor with THI1 in a plasma membrane-delimited manner. Loss-of-function cpk33 mutants were hypersensitive to ABA activation of slow type anion channels and ABA-induced stomatal closure, while the CPK33 overexpression lines showed opposite phenotypes. CPK33 kinase activity was essential for ABA-induced stomatal closure. Consistent with their contrasting regulatory role over stomatal closure, THI1 suppressed CPK33 kinase activity in vitro. Together, our data reveal a novel regulatory role of thiamine thiazole synthase to kinase activity in guard cell signaling.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
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Membrana Celular
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Cálcio
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Arabidopsis
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Proteínas de Arabidopsis
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Estômatos de Plantas
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Canais Iônicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article