Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists at the Scripps Research Institute discover how a plant times its flowering cycle

19.09.2002


Two scientists at The Scripps Research Institute (TSRI) have described how a plant grown in their laboratory uses two sets of proteins to detect the seasons so that it can flower at the right time. And by tinkering with those proteins, the scientists were able to make the plant flower at will.



"We have demonstrated, for the first time, how plants can anticipate the seasons so that they can flower appropriately," says Marcelo Yanovsky, Ph.D., who is a research associate at TSRI and the lead author of the study.

The work should have special relevance to agriculture because the appropriate seasonal control of flowering is a major determinant of crop productivity. The same technology might be used to make certain crops bear fruit faster and in larger and more nutritious yields.


Yanovsky, and TSRI Cell Biology Professor Steve Kay, Ph.D., describe this work in the latest issue of the journal Nature.

How Plants Keep Their Own Appointment Books

Anticipating the seasons is but one of the strategies plants have evolved as a means to cope with the various challenges of their environment.

One of the most obvious changes in the environment is the seasonal variations in weather. Because of the stark seasonal differences in weather in most climates--with long days of burning sunlight in summer and wet, dark, and freezing conditions in winter--plants that have adapted the ability to flower at the best possible time would have had an advantage in evolution.

Scientists have known since the 1920s, when researchers first began experimenting with growing plants under artificial light, that plants flower following a "photoperiodic response"--they flower in seasons when they detect the correct day length. However, until the recent study by Yanovsky and Kay, nobody knew precisely how the plants accomplished this timing.

The timing takes place on the level of individual cells, where circadian "clock" genes have expression levels that follow the solar day. These clock genes ebb and flow throughout the day and year as they are needed, and comprise a complicated set of feedback switch "clockworks" that turn on and off other genes as needed.

For instance, plants use two photoreceptor proteins--the blue light photoreceptor, "cryptochrome," and the red light photoreceptor "phytochrome"--to control other genes.

Like solar-powered clocks, phytochromes and cryptochromes are activated when exposed to daylight and transported to the nucleus of the plant cell where they alter the expression of a number of genes that must be timed. As the sun varies throughout the day, the number and ratio of phytochromes and cryptochromes reaching the nucleus varies, and these changes allow them to delicately control many other genes.

One gene they influence encodes a protein called "CONSTANS." CONSTANS triggers the flowering of the plant, but only when the timing is right--it must first be activated by the right number of cryptochrome and phytochrome molecules.

The expression of CONSTANS also varies throughout the day. It is only expressed (in an inactivate form) in the late afternoon each day. If there is not enough sunlight in the late afternoon, there will not be enough cryptochromes and phytochromes around, CONSTANS will remain inactive, and flowering will not start.

Yanovsky and Kay demonstrated this control mechanism by shifting the expression of CONSTANS towards the morning. By doing so, they were able to make the plants flower earlier during short days, as if they were growing in the long days of spring.

A Good Model Plant

The work was carried out in Kay’s TSRI laboratory, which has for several years been studying the way that plants use "circadian rhythms" to follow the solar day.

The laboratory uses one small, leafy, weed-like relative of the mustard plant, Arabidopsis thaliana. Arabidopsis is a good model organism for several reasons. It is tiny and has a fast generation time, both of which fit well in the modern tight-on-space-and-time laboratory. It also produces an overabundance of seeds at the end of its reproductive cycle. Finally, as a weed, Arabidopsis is easily grown.

Members of the laboratory vary the plants’ environments--the amount of light these test plants receive, for instance--then ask how the plants adjust their own clocks to keep abreast of these changes, looking for which genes are turned on and off when and determining what other molecules are persistently present.

This discovery opens the possibility that we could learn to boost food production by manipulating day length sensitivity of different crops and increasing our capacity to grow them efficiently at different latitudes at different times of the year. "The danger of running out of arable land is very real," says Kay, "and we have to solve the problem of feeding a rapidly increasing population in the next 10 years."

Keith McKeown | EurekAlert!

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>