info:eu-repo/semantics/article
Bell-like homeodomain selectively regulates the high-irradiance response of phytochrome A
Fecha
2009-07Registro en:
Staneloni, Roberto Julio; Rodríguez Batiller, María Jose; Legisa, Danilo Mario; Scarpin, Maria Regina; Agalou, Adamantia; et al.; Bell-like homeodomain selectively regulates the high-irradiance response of phytochrome A; National Academy of Sciences; Proceedings of the National Academy of Sciences of The United States of America; 106; 32; 7-2009; 13624-13629
0027-8424
1091-6490
CONICET Digital
CONICET
Autor
Staneloni, Roberto Julio
Rodríguez Batiller, María Jose
Legisa, Danilo Mario
Scarpin, Maria Regina
Agalou, Adamantia
Cerdan, Pablo Diego
Meijer, Annemarie H.
Ouwerkerk, Pieter B. F.
Casal, Jorge José
Resumen
Plant responses mediated by phytochrome A display a first phase saturated by transient light signals and a second phase requiring sustained excitation with far-red light (FR). These discrete outcomes, respectively so-called very-low-fluence response (VLFR) and high-irradiance response (HIR), are appropriate in different environmental and developmental contexts but the mechanisms that regulate the switch remain unexplored. Promoter analysis of a light-responsive target gene revealed a motif necessary for HIR but not for VLFR. This motif is required for binding of the Bell-like homeodomain 1 (BLH1) to the promoter in in vitro and in yeast 1-hybrid experiments. Promoter substitutions that increased BLH1 binding also enhanced HIR. blh1 mutants showed reduced responses to continuous FR and to deep canopy shadelight, but they retained normal responses to pulsed FR or red light and unfiltered sunlight. BLH1 enhanced BLH1 expression and its promotion by FR. We conclude that BLH1 specifically regulates HIR and not VLFR of phytochrome A.