Natalia Dudareva, associate professor of horticulture, and her colleagues have recently identified the molecular mechanisms that cause petunias and snapdragons to decrease scent production after they've been visited by pollinators such as bees or moths. The researchers also proved that fertilization, the reproductive process that follows pollination, triggers a decline in scent production. In addition, their research has identified a new role for the plant hormone ethylene.

The study will appear in the December issue of The Plant Cell and is published online in advance of print today (Thursday, 11/20) at The Plant Cell Preview.

"Until now, nothing has been known about the molecular mechanisms that shut down scent production after pollination," Dudareva said. "This study gives us a better understanding of how plants regulate floral scent production and how to improve floral scent in unscented flowers."

Over years of breeding for characteristics such as longevity, color and flower size, many commercially-produced flowers have lost their 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.

To her surprise, she found that while petunias and snapdragons rely on some of the same compounds and processes to produce scent, these flowers regulate their post-pollination scent production in different ways at the molecular level.

In all flowers, a variety of substances known as volatile compounds contribute to floral scent, Dudareva said. A volatile compound called methylbenzoate is one of the most abundant scent compounds in many flowers, i
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Contact: Jennifer Cutraro
jcutraro@purdue.edu
765-496-2050
Purdue University
20-Nov-2003