Spatially and genetically distinct control of seed germination by phytochromes A and B.

Détails

ID Serval
serval:BIB_92203271BE9B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Spatially and genetically distinct control of seed germination by phytochromes A and B.
Périodique
Genes and Development
Auteur(s)
Lee K.P., Piskurewicz U., Turečková V., Carat S., Chappuis R., Strnad M., Fankhauser C., Lopez-Molina L.
ISSN
1549-5477 (Electronic)
ISSN-L
0890-9369
Statut éditorial
Publié
Date de publication
2012
Volume
26
Numéro
17
Pages
1984-1996
Langue
anglais
Résumé
Phytochromes phyB and phyA mediate a remarkable developmental switch whereby, early upon seed imbibition, canopy light prevents phyB-dependent germination, whereas later on, it stimulates phyA-dependent germination. Using a seed coat bedding assay where the growth of dissected embryos is monitored under the influence of dissected endosperm, allowing combinatorial use of mutant embryos and endosperm, we show that canopy light specifically inactivates phyB activity in the endosperm to override phyA-dependent signaling in the embryo. This interference involves abscisic acid (ABA) release from the endosperm and distinct spatial activities of phytochrome signaling components. Under the canopy, endospermic ABA opposes phyA signaling through the transcription factor (TF) ABI5, which shares with the TF PIF1 several target genes that negatively regulate germination in the embryo. ABI5 enhances the expression of phytochrome signaling genes PIF1, SOMNUS, GAI, and RGA, but also of ABA and gibberellic acid (GA) metabolic genes. Over time, weaker ABA-dependent responses eventually enable phyA-dependent germination, a distinct type of germination driven solely by embryonic growth.
Mots-clé
Abscisic Acid/metabolism, Arabidopsis/embryology, Arabidopsis/genetics, Arabidopsis Proteins/metabolism, Endosperm/metabolism, Gene Expression Regulation, Plant, Germination, Phytochrome A/metabolism, Phytochrome B/metabolism, Plant Growth Regulators/metabolism, Promoter Regions, Genetic, Seeds/embryology, Seeds/metabolism, Signal Transduction
Pubmed
Web of science
Open Access
Oui
Création de la notice
27/09/2012 19:10
Dernière modification de la notice
08/05/2019 22:05
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