A new study by the University of Toronto is planning to find how plants "breathe" so that can help us breed plants that would better survive the hot summers.
This study shows the first example of a gene that controls how leaves close their surface pores. "It's very exciting," says university's botany professor and senior author Malcolm Campbell. "This is a gene that helps regulate carbon dioxide uptake. If plants are the Earth's lungs, we've just discovered a key piece of information about how the Earth breathes."
The pores on the surface of plant leaves, called stomata, function like little mouths that open and close in response to cues such as light, temperature, and water availability. Using mouse-ear cress, a relative of mustard, cabbage and radish plants, Campbell and co-authors from the university,together with the University of Lancaster, then compared the cooling rates of plants with normal, high and low levels of gene activity. From their data, they were able to link the gene to plant exhalation.
This discovery is another step in understanding how plants might respond to their environment. In hot temperatures, plants keep their mouths "shut" longer than usual, to avoid losing gases and water through evaporation. However, they must open their stomata at some point, both to pick up carbon dioxide needed for photosynthesis and to release oxygen back into the atmosphere. This information will be important to plant breeders looking to improve crop resistance to drought, as well as to those seeking to understand plants' evolutionary responses to climate.
"These genes are of high importance. They allow plants to adapt to changes in light, carbon and water availability. Ultimately, they shape the flux of carbon and water throughout entire ecosystems and affect the carbon cycle on a global-scale." says Campbell.
The study was supported by the University of Toronto, the Natural Sciences and Engineering Research Council of Canada and the Biotechnology and Biological Sciences Research Council of the U.K.
links : http://www.sciencedaily.com/releases/2005/07/050718214711.htm
Zulaikha Razali ( 41600720 )