Scientists have found a new
gene that regulates the daily and yearly physiological cycles
of flowering and seeding.
POSTECH researchers, led by Nam Hong-gil and Kim Jeong-sik,
said that they named the gene FIONA1 after the heroine in
the popular animation ``Shrek.'' In the animation, princess
Fiona is human by day but becomes an ogress at sunset. Fiona
also sounds similar to the term ``flowering'' in Korean.
The research is a foundation for further discoveries of
the plants' clock systems, the team said. To study the gene,
the POSTECH team used mutated cress, a species of weed widely
used in such experiments because of its short seeding cycle
and small genome size.
``We have identified the novel clock component, FIONA1 (FIO1),
which is closely associated with the central oscillator
and is critical to maintaining the correct period length,
but it is not necessary for maintaining the amplitude of
circadian rhythm,'' the researchers said in the paper published
on Plant Cell magazine last week.
The circadian rhythm, which refers to the 24-hour cycle
of plants and animals and other living organisms, is believed
to be corresponding to environmental factors such as temperature
and light. But certain cycling rhythms continue to appear
even under constantly controlled conditions. Furthermore,
plants use their circadian clock to measure changes in day
length, in order to determine the time when it should flower
or seed.
The POSTECH team used genetic mutations of the cress for
the identification and functional characterization of various
components that make the internal clock. As a result, they
found FIONA1, which acts as a clock that controls the plant's
internal clock separately from amplitude and robustness
of other conditions of the circadian period.
The team said that it is just an opening to further discoveries.
``Despite such progress in elucidating the regulatory mechanisms
underlying circadian systems in plants, our understanding
remains very limited and requires the further identification
and functional study of regulatory elements,'' the paper
said.
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