Longer life for flowers.

Research at Purdue University may bud into flowers that last longer, reaping benefits for florists, greenhouses, consumers, and farmers. William R. Woodson, professor horticulture, and graduate students Hanan Itzhaki and Julie M. Maxson have identified the genes that cause flowers to wilt and how this process works.

Previously, it was thought, even among scientists, that flowers wilted because of an unregulated death of the tissues. Woodson is the first to prove that flowers perish because of a specific genetic response. In other words, the flowers don't die of old age. The plants intentionally kill the blooms.

This makes biological sense, Woodson says. The flower of a plant exists to attract insects, or sometimes birds or animals, so that it can be pollinated. A flower can be pollinated only once, so if it did not die after pollination, it would compete with adjacent unpollinated blossoms with no benefit to the plant. Also, because the flower petals don't contain chlorophyll, which produces nutrients from sunlight, they are a drag on the plant's nutrients.

When an insect pollinates a flower, or when a flower is cut from plants, the flower begins producing the plant hormone ethylene. Such production is auto-catalytic, meaning that its presence causes a plant cell to begin to manufacture it. As cells in the plant's ovary produce ethylene, the adjacent cells...