Full Bloom

by Michael Hofferber. Copyright © 1996. All rights reserved.

    "O, ay; as summer flies are in the shambles,
    That quicken even with blowing. O thou weed,
    Who art so lovely fair and smell'st so sweet
    That the sense aches at thee, would thou hadst ne'er been born!"
                                                                                 -- Othello, Act IV, Scene II
As spring gives way to summer, most of the blooms of April and May wilt before the feverish efflorescence of June and July. Gone are the tulips and daffodils and lilies of cooler days and longer nights.
TulipHave you ever wondered why the tulip drops its petals just as orchids are unfolding and while pansies and petunias go on blooming? Is it the heat of summer that makes them fade? Or some aversion to longer days?
Blame it on plant genetics. Flowers don't die off; they are deliberately strangled by the rest of the plant.

A tulip's bloom, however beautiful, serves one purpose to the plant: pollination. A lingering flower saps the energy a plant needs for bulb and seed development. Once pollinated, its beauty is a useless distraction from unpollinated flowers, and so it dies like Desdemona at the hands of Othello, its life tragically cut short.

Horticultural researcher William Woodson of Purdue University questioned how a plant knows when its been pollinated and found that it emits hormones that spread along its tissues. When a flower is cut or pollinated, the flower produces a hormone called ethylene which causes flower petals to shrivel and the plant's ovary to grow.

Orchids and other plants with long-living flowers keep their blooms longer because they are difficult to pollinate, often requiring visits by a certain species of bird or insect. Self-pollinating plants, on the other hand, usually have very short-lived blooms.

Supported with funding from the U.S. Department of Agriculture, Woodson is now looking for ways to genetically interrupt the plant's "kill the bloom" message. He wants to bypass Iago, if you will, and keep Othello enamored of his Desdemona.

Genetically engineered carnations in Woodson's laboratories have maintained their blooms as long as three weeks after being cut. The ramifications for the cut flower industry are, of course, enormous. Longer-lasting blooms mean more sales and more satisfied customers.

And as an offshoot, longer-lasting blossoms on crop plants could increase pollination and reproduction, resulting in potentially higher yields.

"This is the state of man," wrote Shakespeare, "today he puts forth the tender leaves of hope; tomorrow blossoms."

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Flowering and its Manipulation

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Induced Resistance for Plant Defence

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