April 7, 2009

Male flower parts give grapevine perfume

Canadian researchers say they've determined the scent of grapevine flowers comes from pollen grains stored in the anthers, not just the petals.

University of British Columbia scientists from the school's Wine Research Center and Michael Smith Laboratories were studying grapes used to produce Cabernet Sauvignon from British Columbia's Okanagan region when they identified a gene that produces and regulates fragrance from the vines' tiny clusters of green blossoms.

This was a surprise in fundamental plant biology, said Professor Joerg Bohlmann, who led the study. This discovery gives us strong clues to the origin and evolution of fragrant flowers.

Scientists said they believe plants have evolved to produce perfume to attract specific types of pollinators while fending off herbivores and pathogens.

If you ask people where the perfume of a flower comes from, they'll likely say the female parts or the petals, said Bohlmann. Cultivated grapevines are largely self-pollinated, so we believe the fragrance serves more as a defense mechanism to protect their male reproductive tissues from predatory insects, added Bohlmann, who noted further studies on other flowering species might turn up similar mechanisms. It may be more prevalent than we think.

The research appears in the early online edition of the Proceedings of the National Academy of Sciences.