Karrikin-KAI2 signalling provides Arabidopsis seeds with tolerance to abiotic stress and inhibits germination under conditions unfavourable to seedling establishment.
New Phytol
; 219(2): 605-618, 2018 07.
Article
en En
| MEDLINE
| ID: mdl-29726620
The control of seed germination in response to environmental conditions is important for plant success. We investigated the role of the karrikin receptor KARRIKIN INSENSITIVE2 (KAI2) in the response of Arabidopsis seeds to osmotic stress, salinity and high temperature. Germination of the kai2 mutant was examined in response to NaCl, mannitol and elevated temperature. The effect of karrikin on germination of wild-type seeds, hypocotyl elongation and the expression of karrikin-responsive genes was also examined in response to such stresses. The kai2 seeds germinated less readily than wild-type seeds and germination was more sensitive to inhibition by abiotic stress. Karrikin-induced KAI2 signalling stimulated germination of wild-type seeds under favourable conditions, but, surprisingly, inhibited germination in the presence of osmolytes or at elevated temperature. By contrast, GA stimulated germination of wild-type seeds and mutants under all conditions. Karrikin induced expression of DLK2 and KUF1 genes and inhibited hypocotyl elongation independently of osmotic stress. Under mild osmotic stress, karrikin enhanced expression of DREB2A, WRKY33 and ERF5 genes, but not ABA signalling genes. Thus, the karrikin-KAI2 signalling system can protect against abiotic stress, first by providing stress tolerance, and second by inhibiting germination under conditions unfavourable to seedling establishment.
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Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Piranos
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Semillas
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Estrés Fisiológico
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Adaptación Fisiológica
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Arabidopsis
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Germinación
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Proteínas de Arabidopsis
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Plantones
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Furanos
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Hidrolasas
Idioma:
En
Revista:
New Phytol
Asunto de la revista:
BOTANICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Australia
Pais de publicación:
Reino Unido