College Station, Texas
July 30, 2003
Most people who get
too hot and thirsty this summer can quickly grab a cool drink.
Not so for plants. Their
roots keep them lingering in stressful situations - sometimes to
death. Now a
Texas A&M University
researcher has identified a system in a mutant arabidopsis, a
type of weed, that signals to its cells to go on hold until
stressful situations pass.
The involvement of "ER
stress signal pathway" in plant stress adaptation was discovered
by Dr. Hisashi Koiwa, assistant professor of horticultural
sciences, and colleagues. Koiwa is presenting the finding at the
annual meeting of American Society of Plant Biologists this week
(July 26-31) in Hawaii. The findings also will appear in an
upcoming issue of the journal "The Plant Cell."
"A plant will attempt to
regulate itself when stressed by adjusting its cells to the
environment before starting to grow again," Koiwa said. "It's as
if a plant is saying to itself, 'wait, we're in a drought, let's
adjust before we grow anymore.'
"A plant must have a
better stress handling technique," he added. The scientist
explained that when a plant is stressed, it has to rest until it
adjusts because if plant cells continue to divide under stress,
they might "burst." Something signals a plant to pause, he said,
but scientists have never fully studied the systems of plants.
His research, funded in
part with a National Science Foundation grant through
collaboration with Purdue University researchers, describes how
the process works in the mutant arabidopsis.
"It's a natural way
for the plant to sense stress and signal to adjust," Koiwa said.
"The concept is not new, but it had not been fully established
prior to this research."
He said researchers now
can look closer at the process to see what happens in other
plants. In the long term, he said, plant breeders might use this
knowledge to breed plants that are more able to adjust to
various environment stresses such as extreme temperatures or the
lack or abundance of water.
"If a species of plants
can't take a drought, perhaps a plant breeder could enhance the
ER stress signal pathway to enable that species to be more
adaptable so that it can survive and grow well," Koiwa said.
"Otherwise, in many cases, a plant responds to such stress too
late to recover."
But more information is
needed. Researchers now know there is a system, but don't
understand why it works as it does. He said it is similar to
understanding that the muscle system in humans allow for
movement, but knowing why is necessary to find medical answers
for failed muscles. Researchers now may take the study a step
further, Koiwa said, to find out the "mechanism a plant uses to
hold on for the stress and the mechanism a plant uses to
indicate it is ready to start cell division again."
Writer: Kathleen
Phillips, (979) 845-2872,
ka-phillips@tamu.edu |