A team of scientists from Canada, Spain and the United States
has identified a key gene that allows plants to defend themselves
against environmental stresses like drought, freezing and heat.
"Plants have stress hormones that they produce naturally
and that signal adverse conditions and help them adapt,"
says team member Peter McCourt, a professor of cell and systems
biology at the University of Toronto. "If we can control
these hormones we should be able to protect crops from adverse
environmental conditions which is very important in this day
and age of global climate change."
The research team, led by Sean Cutler of the University of
California, Riverside, has identified the receptor of the key
hormone in stress protection called abscisic acid (ABA). Under
stress, plants increase their ABA levels, which help them survive
a drought through a process not fully understood. The area of
ABA receptors has been a highly controversial topic in the field
of plant biology that has involved retractions of scientific
papers as well as the publication of papers of questionable
significance. A receptor is a protein molecule in a cell to
which mobile signaling molecules may attach. Usually at the
top of a signaling pathway, the receptor functions like a boss
relaying orders to the team below that then executes particular
decisions in the cell. "Scientists have been trying to
solve the ABA receptor problem for more than 20 years, and claims
for ABA receptors are not easily received by the scientific
community," says Cutler.
This team used a new approach called chemical genomics to identifying
a synthetic chemical, designated pyrabactin, which specifically
activates an ABA receptor in the model laboratory plant Arabidopsis.
With pyrabactin in hand it was now possible to directly identify
the ABA receptor. "This approach not only found a gene
that had been long sought by the plant science research community
but also showed that chemical genomics can identify new chemicals
like pyrabactin that may have profound impacts on the way we
farm in both the developing and developed world," says
The study results will appear April 30 in Science Express and
in the May 22 issue of Science magazine. Lead author Sean Cutler
is a former University of Toronto scientist who is now an assistant
professor of plant cell biology in the Department of Botany
and Plant Sciences at the University of California, Riverside.
In addition to the University of Toronto and the University
of California, Riverside, team members were from University
of California, San Diego, Universidad Politecnica, Spain, the
University of Ontario Institute of Technology, University of
California, Santa Barbara; and the Medical College of Wisconsin.
Research was funded by the Canada Research Chair program, the
Natural Sciences and Engineering Research Council. the National
Science Foundation and the National Institutes of Health.
Cell and Systems Biology
University of Toronto
Arts & Science Communications
University of Toronto