INVESTIGADORES
YANOVSKY Marcelo Javier
artículos
Título:
Blue Rhythms Between Gigantea and Phytochromes
Autor/es:
CREPY, M; YANOVSKY, MJ; CASAL, JJ
Revista:
Plant Signaling and Behavior
Referencias:
Año: 2007 vol. 2 p. 530 - 532
Resumen:
GIGANTEA (GI) is involved in the promotion of flowering by long days, in light input
to the circadian clock, and in seedling de‑etiolation under continuous red light or blue
light but not under continuous far‑red light (FR). Since red‑light effects are mediated largely
by phytochrome B and those of FR by phytochrome A (phyA), GI was considered not to
affect phyA signaling. However, recent observations using brief FR pulses indicate that
GI does affect the very‑low‑fluence response (VLFR) and not the high‑irradiance response
(HIR) pathway of phyA. Seed germination, seedling de‑etiolation and gene expression
showed rhythmic sensitivity to FR pulses. GI affected the magnitude but not the rhythmic
pattern of the responses, indicating that GI regulation of phyA signaling does not derive
from its effects on the clock. Here we show that despite de above divergence between
VLFR and HIR, both pathways require the bZip transcription factor HY5. Furthermore, the
blue‑light phenotype of gi is not mediated by phyA, indicating a role of GI in the control
of cryptochrome signaling. These findings illustrate features of plant signaling networks.gi is not mediated by phyA, indicating a role of GI in the control
of cryptochrome signaling. These findings illustrate features of plant signaling networks.