Saturday, October 8, 2011

With altered genes, plants adjust to climate

Katherine Long in the Brown Daily Herald: Newly discovered links between a plant's genetic variations and climate change may­ reduce the agriculture industry's reliance on pesticide use, according to a paper by researchers in the University's Schmitt Lab published yesterday in the journal Nature.

The study, which examined variations in the plant Arabidopsis thaliana, took roughly five years to complete and involved 9,420 specimens grown in England, France, Spain and Finland, said Alexandre Fournier-Level GS, the first author of the paper. Researchers used genetic analysis and visible indicators of a plant's fitness to show that local genomic adaptation is definitively shaped by variations in climate. Climate-specific adaptations give some plants "home-court advantages" compared to plants of the same species grown elsewhere.

"We already know that a plant that comes from the north does better in the north, and a plant coming from the south does better in the south," Fournier-Level said. "But is this true on the genomic level? That's what we wanted to find out. And yes, it is." The study also proved that beneficial adaptations do not, as previously believed, always spread to an entire population — a difference in understanding adaptation that Fournier-Level said was "fundamental."
Specimens with genotypic advantages live side-by-side with specimens whose genes are unaltered. If those two plants breed, they can create a hybrid adapted to a broader range of conditions — "and then it's all peace and love in the plant kingdom," he said.

Fournier-Level said the results could be especially important for farmers looking to grow crops in climates rendered increasingly diverse by carbon emissions.

"Right now, if a farmer wants to grow corn from Mexico in Montana, that farmer needs to artificialize the environment with fertilizer and pesticides," he said. But the study suggests that farmers may instead be able to grow corn that has genes specifically adapted to Montana, increasing crop yield without the use of potentially harmful chemicals....

Early Examples of Gene Silencing in Transgenic Plants. TGS: Normally when two plants harboring separate transgenes encoding resistance to kanamycin (kan) or hygromycin (hyg), respectively, are crossed, 50% of the progeny are resistant to the individual antibiotics and 25% are resistant to a combination of both (top). In cases of silencing, expression of the KAN marker is extinguished in the presence of the HYG marker, as indicated by only 25% kan resistance and no double resistance (middle). PTGS: Transformation of wild-type Petunia (bottom left) with a transgene encoding a pigment protein can lead to loss of pigment (white areas) owing to cosuppression of the transgene and homologous endogenous plant gene. Matzke MA, Matzke AJM (2004) Planting the Seeds of a New Paradigm. PLoS Biol 2(5): e133 http://dx.doi.org/10.1371/journal.pbio.0020133. Wikimedia Commons via a Public Library of Science Journal, under the Creative Commons Attribution 2.5 Generic license

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