Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic snooze button governs timing of spring flowers

11.08.2006
In the long, dark days of winter, gardeners are known to count the days until spring. Now, scientists have learned, some plants do exactly the same thing.

Addressing scientists here today (Aug. 9) at a meeting of the American Society of Plant Biologists, University of Wisconsin-Madison researcher Richard Amasino described studies that have begun to peel back some of the mystery of how plants pace the seasons to bloom at the optimal time of year.

"Flowering at the right time is all about competition," says Amasino, Howard Hughes Medical Institute Professor and UW-Madison professor of biochemistry.

Amasino and his colleagues have studied, in particular, the behaviors of biennial plants, which require long periods of exposure to the cold to initiate flowering in the spring. What they have found reveals some of the complex interplay of genes and environment and provides hints that, one day, it may be possible to exert precise control over flowering, a process essential for plant reproduction and fruiting and that has enormous implications for agriculture.

Flowers are the reproductive organs of plants and are responsible for forming seeds and fruit. As their name implies, biennials complete their life cycles in two years, germinating, growing and overwintering the first year. The second year, the plants flower in the spring and die back in the fall.

That biennial strategy, Amasino explains, arose as flowering plants, which first evolved some 100 million years ago during the age of the dinosaurs, spread to fill the niches of nature. Spring blooming confers numerous advantages, not the least of which is leafing out and flowering before the competition.

But how do the plants know when to flower?

"If you carve out that niche, you need to get established in the fall, but you need to make darn sure you don't flower in the fall," Amasino says. In the case of biennials, "the plants can somehow measure how much cold they've been exposed to, and then they can flower rapidly in the spring niche."

Exposure to the cold triggers a process in plants known as vernalization, where the meristem - a region on the growing point of a plant where rapidly dividing cells differentiate into shoots, roots and flowers - is rendered competent to flower.

In a series of studies of Arabidopsis, a small mustard plant commonly used to study plant genetics, Amasino and his colleagues have found there are certain critical genes that repress flowering.

"The plants we've studied, primarily Arabidopsis, don't flower in the fall season because they possess a gene that blocks flowering," Amasino explains. "The meristem is where the repressor (gene) is expressed and is where it is shut off."

The key to initiating flowering, according to the Wisconsin group's studies, is the ability of plants to switch those flower-blocking genes off, so that they can bloom and complete their pre-ordained life cycles.

But how that gene was turned off was a mystery until Amasino and his group found that exposure to prolonged cold triggered a molecular process that effectively silenced the genes that repress flowering.

Another processes known as bud dormancy, which is similar to vernalization, occurs in many plants that grow in temperate climates. "Bud dormancy is not broken until the plant has 'counted' a sufficient number of days of cold to ensure that any subsequent warm weather actually indicates that spring has arrived," Amasino says.

The Wisconsin team led by Amasino has worked out much of the process of vernalization, and their hope is to add to knowledge of other cold-regulated processes such as the regulation of bud dormancy in trees. Bud dormancy may be similar to vernalization or, the Wisconsin scientists adds, it may be controlled by a completely different mechanism.

"But our study of vernalization may help us get our foot in the door," Amasino says. "It gives us a basis to test whether there are similarities."

Knowing the genes that control flowering and how they work provides a much more detailed working knowledge of plants, many that are useful to humans and some of great economic importance, Amasino explains.

"This is important agriculturally," he notes. "There are many crops - cabbage, beets - that we don't want to flower. Many of the cultivated varieties we use are never exposed to cold in a typical farmer's field growing season."

When that is the case, a cold snap can fool sugar beets, for example, into flowering, a process that can ruin the crop by redirecting nutrients from the valuable root to the production of seeds and flowers.

And although Amasino and his group have demystified some of the molecular underpinning of the familiar process of flowering, the biochemist emphasizes that much of the fine biochemical detail remains to be worked out.

Richard Amasino | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>