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Gene aromatherapy
Scientists
aim to fix flowers’ wilting scents
through genetic engineering
Feb. 9, 2005
Special to World Science
Genetic engineering is often used to change our food. But soon, it may become a tool for winning our hearts.
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Among the flowers that scientists have
attempted to genetically engineer for scent are petunias. (Photo
courtesy Cornell University.)
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Scientists are designing flowers with genetically modified or enhanced scents, in an attempt to replace fragrances that have vanished over decades of flower breeding.
As breeders worked to develop longer-lasting, taller, bigger strains of flowers, gradually the fragrances disappeared, the researchers say.
Smell is the sense most closely linked to our emotions. At a whiff, long-forgotten memories and feelings can surge back like an avalanche. It’s partly in hopes of tapping into this pipeline to the soul that lovers give flowers, symbols since time immemorial of everything that’s fresh, natural and unblemished.
And soon, scientists, businessmen and patent lawyers will be right there to help them.
While there’s nothing new about industrially designed fragrances, to genetically engineer them and put them in flowers is an unprecedented
move. Scientists have already taken the first tentative steps to accomplish
it.
Several research groups have engineered petunia and carnation plants with extra scent-making genes, according to University of Michigan Professor Eran Pichersky. The added genes came from
Clarkia Breweri, a sweet- smelling, violet flower common in coastal California. Pichersky reported the experiments in the November-December 2004 issue of
American Scientist, a magazine published by Sigma Xi, a nonprofit scientists’ group.
These experiments failed, Pichersky wrote: the added genes didn’t produce enough scent, and spread themselves all over the plants rather than concentrating in the flowers as desired. A new generation of experiments aimed at correcting these shortcomings is underway, he wrote.
These “pioneering attempts” have also revealed much about the complex mechanisms by which flowers produce fragrances, wrote Natalia Dudareva of Purdue University in West Lafayette, Indiana, in the February 2005 issue of the scientific journal
Current Opinion in Plant Biology. These efforts, she added, have also “built new avenues for future successful metabolic engineering.”
Metabolic engineering is a form of genetic engineering aimed at changing the way living things metabolize, or rearrange the nutrients they take in into different chemicals. Some of these chemicals, in plants, are known as volatiles — compounds that evaporate easily into the air, and thus make useful fragrances.
These efforts could breathe renewed vigor into the $30 billion-per-year ornamental floral industry, Pichersky wrote.
The declining smell value of many flowers has been a major item of concern to growers. “Go to a florist and observe the customers,” said the University of Florida’s David Clark in a press release from the school two years ago. “The first thing they do is attempt to smell the flowers. They’re often frustrated when they discover they can’t.”
Scientists believe the problem arose because breeders have been selecting flowers for characteristics such as shelf life, color and size—almost everything but scent. “It makes sense. To increase shelf life, a flower needs to save energy, and maybe the trade-off was that these flowers don’t expend energy on producing scent anymore,” Dudareva said in a 2003 press release from Purdue.
But some critics of genetic engineering are apprehensive about the notion of genetically enhancing flowers. Many of these critics are already fighting the use of genetic engineering in food; they say it’s unhealthy and damages the environment, although the scientists and companies that develop the engineered products claim the opposite.
For now, the matter of genetically enhanced flowers is beneath the radar screen of many of the activists.
“I think some people would shy away” from enhanced flowers, said Juliet McFarlane, a founding member of the Network of Concerned Farmers, an Australian group opposed to genetic engineering.
Partly this aversion might appear for emotional reasons, she said, but a more practical issue is that genetically modified crops can raise prices for growers. This is because once the stores and supermarkets get used to distributing modified
products, small growers are forced to produce them. That raises their prices because they have to buy the patented seeds sold by the companies that
engineer them.
“I would be much more concerned about who’s going to end up controlling the fees,” she said. “I suspect it’s not about the scent, it’s about the money.”
—EJL
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Front image courtesy the
Jefferson County, Colo. Public Rose Garden
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