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Blooms with modified scents in the works

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Blooms with modified scents in the works
Ever wanted a rose that smelled like bananas? Maybe a petunia that
reeked of root beer? Researchers at the University of Florida
Gainesville have isolated 13 genes in flowers that are key to a
blossom’s fragrance.

Feb. 25, 2010 – Shakespeare famously wrote, “That which we call a rose by any other
name would smell as sweet.” With all due respect to the Bard, University of Florida researchers may have to disagree: no matter what you call a flower, its scent can be changed.

A team at UF’s Institute of Food and Agricultural Sciences
has uncovered some of the genes that control the complex mixture of
chemicals that comprise a flower’s scent, opening new ways of “turning
up” and “tuning” a flower’s aromatic compounds to produce desired
fragrances.

“For a long time, breeders have mostly focused on how flowers look, their size, color and how long blooms last,” said David Clark, a professor of environmental horticulture. “But scent has gotten left behind. Go to a florist and try to smell the flowers. You probably won’t get what you expect.”

Over the years, Clark says, breeders have selected flowering plants
that produce bigger, more attractive flowers with long vase lives; but
in doing so, they may have been inadvertently selecting plants that
were willing to devote less to producing fragrance.

That may change. For example, a customer may someday be able to walk
into a florist and select from scented or unscented varieties of the
same flower.

In work published in the January issue of The Plant Journal and the
February issue of Phytochemistry, the researchers describe how various
genes in petunias help regulate the amount of the 13 major aromatic
compounds in that flower’s fragrance.

The work will help researchers control the levels of these
compounds, adjusting a flower’s fragrance while also producing more or
less of it.

In the papers, the researchers also describe some of the more
fundamental aspects of how flowers produce scent. For example, they
observed that the scents are largely manufactured in the petunia
flower’s petals, and that scent production is activated when the flower
opens.

The studies are part of an ongoing effort to isolate the chain
reaction responsible for producing scent, so that fragrances can be
modified without interfering with other flower qualities, said Thomas
Colquhoun, a UF environmental horticulture researcher and first author
on both papers.

For more than a decade, Clark and his colleagues have combed through
more than 8,000 petunia genes. The search has yielded some interesting
finds.

For example, the gene that produces the compound that gives rose oil its distinctive scent also makes tomatoes taste good.

By manipulating this gene, UF researchers led by horticulture professor Harry Klee
have been able to create tomatoes with more flavor. Klee, Clark and
colleagues are now working with plant breeders and taste specialists to
prepare the tomato for the marketplace. Better smelling roses are also
in the pipeline.

“The taste of food, the smell of a flower — these are things that
enrich our lives in ways we don’t fully understand yet,” Clark said.
“Learning how plants interact with us and their environment brings us
closer to truly appreciating what the natural world has to offer.”