Control of Circadian Rhythms and Photoperiodic Flowering by the Arabidopsis GIGANTEA Gene
Deok Hoon Park,
1*
David E. Somers,
2*
Yang Suk Kim,
1
Yoon Hi Choy,
1
Hee Kyun Lim,
1
Moon Soo Soh,
1
Hyo Jung Kim,
1
Steve A. Kay,
2
Hong Gil Nam
1
Photoperiodic responses in plants include flowering that is
day-length-dependent. Mutations in the Arabidopsis thaliana
GIGANTEA (GI) gene cause photoperiod-insensitive
flowering and alteration of circadian rhythms. The GI gene
encodes a protein containing six putative transmembrane domains.
Circadian expression patterns of the GI gene and the
clock-associated genes, LHY and CCA1, are altered
in gi mutants, showing that GI is required for maintaining circadian amplitude and appropriate period length of these genes. The
gi-1 mutation also affects light signaling to the clock,
which suggests that GI participates in a feedback loop of the plant circadian system.
1 Department of Life Science, Pohang University
of Science and Technology, Pohang, Kyungbuk, 790-784, Korea.
2 Department of Cell Biology and National Science
Foundation Center for Biological Timing, The Scripps Research
Institute, 10550 North Torrey Pines Road, La Jolla, CA 92307, USA.
*
These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail:
hgn{at}bric.postech.ac.kr
