EAST LANSING, Mich. New ground broken by Michigan State University biochemists helps explain how plants protect themselves from freezing temperatures and could lead to discoveries related to plant tolerance for drought and other extreme conditions.
"This brings together two classic problems in plant biology," said Christoph Benning, MSU professor of biochemistry and molecular biology. "One is that plants protect themselves against freezing and that scientists long thought it had something to do with cell membranes, but didn't know exactly how.
"The other is the search for the gene for an enigmatic enzyme of plant lipid metabolism in the chloroplasts," in other words, how lipids, which are membrane building blocks, are made for the plant cell organelles responsible for converting solar energy into chemical energy by photosynthesis.
In an article published online this week by the journal Science, Benning and his then-doctoral degree candidate Eric Moellering and technical assistant Bagyalakshmi Muthan describe how a particular gene leads to the formation of a lipid that protects chloroplast and plant cell membranes from freeze damage by a novel mechanism in Arabidopsis thaliana, common mustard weed. Working on his dissertation project under Benning, Moellering identified a mutant strain of Arabidopsis that can't manufacture the lipid and linked this biochemical defect to work done by others who originally described the role of the gene in freeze tolerance, but did not find the mechanism.
"One of the big problems in freezing tolerance or general stress in plants is that some species are better at surviving stress than others," Moellering said. "We are only beginning to understand the mechanisms that allow some plants to survive while others are sensitive."
There is no single mechanism involved in plant freezing tolerance, Moellering added, so he can't say that his findings will lead any time so
|Contact: Mark Fellows|
Michigan State University