PT  - JOURNAL ARTICLE
AU  - Kircher, Stefan
AU  - Kozma-Bognar, Laszlo
AU  - Kim, Lana
AU  - Adam, Eva
AU  - Harter, Klaus
AU  - Schäfer, Eberhard
AU  - Nagy, Ferenc
TI  - Light Quality–Dependent Nuclear Import of the Plant Photoreceptors Phytochrome A and B
AID  - 10.1105/tpc.11.8.1445
DP  - 1999 Aug 01
TA  - The Plant Cell
PG  - 1445--1456
VI  - 11
IP  - 8
4099  - http://www.plantcell.org/content/11/8/1445.short
4100  - http://www.plantcell.org/content/11/8/1445.full
SO  - Plant Cell1999 Aug 01; 11
AB  - The phytochrome (phy) family of plant photoreceptors controls various aspects of photomorphogenesis. Overexpression of rice phyA–green fluorescent protein (GFP) and tobacco phyB–GFP fusion proteins in tobacco results in functional photoreceptors. phyA–GFP and phyB–GFP are localized in the cytosol of dark-adapted plants. In our experiments, red light treatment led to nuclear translocation of phyA–GFP and phyB–GFP, albeit with different kinetics. Red light–induced nuclear import of phyB–GFP, but not that of phyA–GFP, was inhibited by far-red light. Far-red light alone only induced nuclear translocation of phyA–GFP. These observations indicate that nuclear import of phyA–GFP is controlled by a very low fluence response, whereas translocation of phyB–GFP is regulated by a low fluence response of phytochrome. Thus, light-regulated nucleocytoplasmic partitioning of phyA and phyB is a major step in phytochrome signaling.