Antagonistic Roles of PhyA and PhyB in Far-Red Light-Dependent Leaf Senescence in Arabidopsis thaliana.
Plant Cell Physiol
; 59(9): 1753-1764, 2018 Sep 01.
Article
em En
| MEDLINE
| ID: mdl-30099525
ABSTRACT
Leaf senescence is regulated by diverse developmental and environmental factors to maximize plant fitness. The red to far-red light ratio (RFR) detected by plant phytochromes is reduced under vegetation shade, thus initiating leaf senescence. However, the role of phytochromes in promoting leaf senescence under FR-enriched conditions is not fully understood. In this study, we investigated the role of phyA and phyB in regulating leaf senescence under FR in Arabidopsis thaliana (Arabidopsis). FR enrichment and intermittent FR pulses promoted the senescence of Arabidopsis leaves. Additionally, phyA and phyB mutants showed enhanced and repressed senescence phenotypes in FR, respectively, indicating that phyA and phyB antagonistically regulate FR-dependent leaf senescence. Transcriptomic analysis using phyA and phyB mutants in FR identified differentially expressed genes (DEGs) involved in leaf senescence-related processes, such as responses to light, phytohormones, temperature, photosynthesis and defense, showing opposite expression patterns in phyA and phyB mutants. These contrasting expression profiles of DEGs support the antagonism between phyA and phyB in FR-dependent leaf senescence. Among the genes showing antagonistic regulation, we confirmed that the expression of WRKY6, which encodes a senescence-associated transcription factor, was negatively and positively regulated by phyA and phyB, respectively. The wrky6 mutant showed a repressed senescence phenotype compared with the wild type in FR, indicating that WRKY6 plays a positive role in FR-dependent leaf senescence. Our results imply that antagonism between phyA and phyB is involved in fine-tuning leaf senescence under varying FR conditions in Arabidopsis.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arabidopsis
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Folhas de Planta
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Regulação da Expressão Gênica de Plantas
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Fitocromo A
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Fitocromo B
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Luz
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant Cell Physiol
Assunto da revista:
BOTANICA
Ano de publicação:
2018
Tipo de documento:
Article