Featured Research

from universities, journals, and other organizations

Genes For Unusual "Flower Within A Flower" Are Identified By UCSD Scientists

Date:
May 12, 2000
Source:
University Of California, San Diego
Summary:
One of the more unusual curiosities of the plant world—among roses and other flowers—is a flower within a flower within a flower. The abnormality has long puzzled geneticists, who have sought for years in vain for the genes responsible for this condition. But an important part of the mystery has been solved by a team of biologists at the University of California, San Diego.

Gertrude Stein once wrote that a rose is a rose is a rose. But not all roses consist of mundane single flowers. One of the more unusual curiosities of the plant world—among roses and other flowers—is a flower within a flower within a flower.

Related Articles


The abnormality has long puzzled geneticists, who have sought for years in vain for the genes responsible for this condition. But an important part of the mystery has been solved by a team of biologists at the University of California, San Diego.

In a cover story in the May 11th issue of Nature, the scientists report that they have identified a trio of genes that produce this flower within a flower, one of the earliest-recognized abnormalities in flowers.

First described more than 2,000 years ago and initially referred to as a "monstrous flower," the abnormality is now called the "double flower" and is prized within the flower industry for its attractiveness. Many roses, camellias and impatiens, as well as a host of other plants produce these double flowers, which are grown from plant cuttings because the plants, having lost their reproductive organs, are effectively sterile.

Plants do not normally produce double flowers in the wild and, in their study, the UCSD biologists discovered why. Only when three virtually identical genes within the plant’s cells are all mutated, they found, is the result a flower within a flower within a flower, a repetitive process that continues indefinitely—or at least until the smallest organs of the flower can’t be detected.

"They endlessly reiterate flower organs, they just keep on going and going," says Martin F. Yanofsky, a professor of biology at UCSD who headed the research team, which included

UCSD biologists Soraya Pelaz and Gary S. Ditta. Elvira Baumann and Ellen Wisman of the

Max-Planck Institute for Breeding Research in Koln, Germany also participated in the study, which was financed by the National Science Foundation and the National Institutes of Health.

Normal flowers consist of a series of four rings or "whorls." The outermost whorl is made up of sepals, the green leaf-like organ that normally surrounds the flower bud before it opens. Inside the sepals is a ring of petals, then a ring of stamens, the male reproductive structures, and at the center are the carpels (often referred to as the pistils), the female reproductive structures.

When the three genes found by the UCSD scientists are all mutated, the petals, stamens and carpels are all converted into sepals, resulting in the double-flower character. "Because these genes are necessary for petals, stamens and carpels to form in a normal flower, they are master regulators of flower development," says Yanofsky.

The important role of these three genes had long been hidden from geneticists, because all three genes are virtually identical, meaning that the UCSD researchers had to mutate each one of these genes and then combine the three mutations into a single plant. This technique, referred to as "reverse genetics," took years of effort in the laboratory, but finally paid off in the discovery of the triple mutant in the weed plant, Arabidopsis, which has long been used as a plant model by geneticists.

"This was a heroic undertaking, as three genes had to be knocked out in order for the function to be revealed," says Detlef Weigel, an expert on flower development who is an associate professor at the Salk Institute for Biological Studies. "This paper will make it into the textbooks."

Botanists proposed hundreds of years ago that the sepal, petal, stamen and carpel organs that make up a typical flower represent modified leaves. But despite the rapid progress that many researchers around the world have made over the past decade in isolating key flower-control genes, they have not been able to convert leaves into each of the flower organs.

"This discovery may add the missing piece of the puzzle, as we now know that these genes are necessary for the formation of the different flower organs," says Yanofsky. "It will now be interesting to directly test this idea by turning on these genes in leaves, where they are normally turned off. This could well make for some very interesting new plant varieties that have, for example, colorful petals replacing the normal leaves."

###

Media Contact: Kim McDonald (858) 534-7572

Images of normal Arabidopsis flower, double flower, and flower organs available at: http://ucsdnews.ucsd.edu/newsrel/science/mcflower.htm Credit: Soraya Pelaz, UCSD


Story Source:

The above story is based on materials provided by University Of California, San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, San Diego. "Genes For Unusual "Flower Within A Flower" Are Identified By UCSD Scientists." ScienceDaily. ScienceDaily, 12 May 2000. <www.sciencedaily.com/releases/2000/05/000512083513.htm>.
University Of California, San Diego. (2000, May 12). Genes For Unusual "Flower Within A Flower" Are Identified By UCSD Scientists. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2000/05/000512083513.htm
University Of California, San Diego. "Genes For Unusual "Flower Within A Flower" Are Identified By UCSD Scientists." ScienceDaily. www.sciencedaily.com/releases/2000/05/000512083513.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins