East Lansing, Michigan
October 7, 2008
Michigan State University plant scientists have discovered
another piece of the genetic puzzle that controls how plants
respond to high temperatures. That may allow plant breeders to
create new varieties of crops that flourish in warmer, drier
climates.
The MSU researchers found that the gene bZIP28 helps regulate
heat stress response in Arabidopsis thaliana, a member of the
mustard family used as a model plant for genetic studies. This
is the first time bZIP28 has been shown to play a role heat
tolerance. The research is published in the Oct. 6 issue of the
Proceedings of the National Academy of Sciences.
"We also found that bZIP28 was responding to signals from the
endoplasmic reticulum, which is the first time the ER has been
shown to be involved with the response to heat," said Robert
Larkin, MSU assistant professor of biochemistry and molecular
biology and corresponding author of the paper. "We're finding
that heat tolerance is a more complex process than was first
thought."
Previous research has shown that the nucleus, the "brain" of the
cell, and cytosol, the fluid inside cells, play a role in how
plants respond to heat. The endoplasmic reticulum, a membrane in
the cell that consists of small tubes and sac-like structures,
is mainly responsible for packaging and storing proteins in the
cell.
According to Christoph Benning, MSU professor of biochemistry
and molecular biology and a member of the research team, the
scientists were looking for genes that turn other genes on and
off and are tied to cell membranes. These membrane-tethered gene
switches are seen in animals but hadn't been studied in great
detail in plants.
"The bZIP28 protein is anchored in the endoplasmic reticulum,
away from its place of action," Benning explained. "But when the
plant is stressed by heat, one end of bZIP28 is cut off and
moves into the nucleus of the cell where it can turn on other
genes to control the heat response. Understanding how the whole
mechanism works will be the subject of more research."
Plants with an inactive bZIP28 gene die as soon as temperatures
reach a certain level.
Other scientists on the research team are Federica Brandizzi,
MSU associate professor of plant biology and member of the Plant
Research Lab, and Hangbo Gao, former MSU post-doctoral research
associate.
The work was sponsored by the MSU-DOE Plant Research Lab.
Benning's research also is supported by the Michigan
Agricultural Experiment Station.
Michigan State University has been advancing knowledge and
transforming lives through innovative teaching, research and
outreach for more than 150 years. MSU is known internationally
as a major public university with global reach and extraordinary
impact. Its 17 degree-granting colleges attract scholars
worldwide who are interested in combining education with
practical problem solving. |
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