Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Winter weather turns on flowering gene

08.01.2004


In four months, when flower buds spring up from the ground, you may wonder how plants know it’s time to bloom. This question has baffled plant biologists for years. Now, scientists at the University of Wisconsin-Madison have an answer: a gene that functions as an alarm clock to rouse certain plants from a vegetative state in the winter to a flowering state in the spring.

According to the researchers, the findings, published in the Jan. 8 issue of the journal Nature, could lead to new methods for manipulating the productivity of crop plants, as well as a better understanding of how organisms control the fate of their cells.

Most people may not know that some of our favorite salad ingredients - carrots, cabbage, radishes, beets and parsley - take two seasons to flower and produce seeds because we harvest them before they have the chance to flower. These plants, called biennials, require a season of cold to flower.



"We’ve known that winter does something to the plant’s growing tip, or meristem, and makes it competent to flower," says Richard Amasino, a UW-Madison biochemistry professor and senior author of the paper. "If biennials don’t go through winter, they won’t flower." But why, he adds, has remained a mystery.

This mystery started to unravel in 1999, when Amasino and his colleagues identified two genes central to the flowering of Arabidopsis thaliana, a small, flowering plant that’s a member of the mustard family. The genes work together to block blossoming. As they observed, one of these genes is no longer expressed in the spring, when the plants can flower and complete their life cycle.

How winter switches off this flower-inhibiting gene in the second growing season, says Amasino, was the next obvious question. So, the Wisconsin scientist and UW-Madison biochemistry graduate student Sibung Sung looked to a biennial variety of Arabadopsis, a plant that’s widely used as a model organism in plant biology and genetics. They screened for mutants that wouldn’t bud after surviving temperatures just above freezing, and they found three - all lacking a gene now called VIN3.

After further investigation, the researchers learned that an extended period of cooler temperatures prompts the VIN3 gene to turn on. Once activated, the gene starts the process of vernalization, whereby the plant becomes competent to flower after exposure to cold. As this process begins, the expression of the flower-suppressing gene identified in 1999 wanes until it is completely blocked.

The researchers report that the VIN3 gene is expressed only after plants have been exposed to conditions effective for vernalization, suggesting that the VIN3 gene functions as an alarm clock rousing biennial plants to bloom.

But how do plants know they’ve been exposed to the right temperature for the right amount of time? "This is an intriguing question," says Sung. "Without a nervous system, plants must have a mechanism by which they can remember they have been through the winter season." Although plants don’t have a brain like humans do, they do have cellular machinery that appears to remember cold exposure, according to the new research.

The Wisconsin scientists show that the expression of VIN3, which occurs after exposure to cold, initiates a series of changes in one of the flower-suppressing genes. Specifically, VIN3 activation permanently modifies the structure of histones, a group of proteins over which DNA is wrapped. These changes block the flower-suppressing gene, switching the plant from a fixed state where it won’t flower to a fixed state where it can flower.

Scientists speculate that changes in histone structure play a major role in the development of higher organisms and the formation of cancer cells. Says Sung, "Histone changes in model plants could give us the opportunity to extend our understanding of how organisms control their cell fates during development."

The findings by Amasino and Sung also could lead to improvements in agriculture.

"This new molecular understanding could provide information to help design tools to manipulate flowering," the biochemistry professor says. For example, agronomists could engineer biennial crops that lack VIN3 and never flower, potentially increasing yield. But as Amasino clarifies, he’s in the business of basic science - it’s up to others to use the information.

Further Contact: Sibum Sung, 608-262-4640, sbsung@biochem.wisc.edu

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

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>