Sydney: A signal found
in plants could act as a drought alarm, allowing them to adapt to
such extreme conditions.
Scientists stumbled on the signal while trying to understand how
different parts of the cell chat with one another in the
Arabidopsis thaliana, a kin of canola, under drought conditions.
A series of connected pathways, like the production lines of a
factory, are inside every plant and animal cell. They are
regulated by chemical signals and inputs, which can come from many
Scientists have proposed for a while that chemical signals must be
sent by a particular "plant department", or organelle, to the
nucleus, the cell's control centre, for plants to become aware of
and adapt to harsh conditions, according to an Australian National
University (ANU) statement.
"The chloroplast is the plant organelle that converts light into
food. The nucleus directs assembly and function of the chloroplast
and this requires cross-talk between the two," said ANU's Gonzalo
Estavillo, who led the study with Barry Pogson, a professor.
Now, research on a mutant variety of Arabidopsis has led to the
discovery of a signal to the nucleus which is important in its
response to drought.
The Arabidopsis mutant plant lacked a protein called SAL1, which
breaks down a small molecule further down the production line
As the protein was absent, the production line was broken, so PAP,
which is usually found in the chloroplast, ended up building up in
Surprisingly, this became a kind of a drought alarm, telling the
plant to save water. Consequently these mutant plants survived 50
percent longer in drought conditions.