Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New mechanisms uncovered explaining frost tolerance in plants

26.09.2016

Defying frost and the cold with hormones

Plants cannot simply relocate to better surroundings when their environmental conditions are no longer suitable. Instead, they have developed sophisticated molecular adaptation mechanisms. Scientists at the Technical University Munich (TUM) in cooperation with the Helmholtz Center Munich and the University of Nottingham have been able to demonstrate that brassinosteroids, which until now have mainly been regarded as growth hormones, increase the resistance of plants against frost.


Pictured are frozen flowers of an apple tree in South Tyrol, Italy that have been protected from damage by late frost with frost-protection sprinkling. Eremina et al show that in the freezing tolerance of plants steroid hormones take part, and elucidate molecular pathways, which contribute to this activity. (Photo: courtesy of D. Mitterer-Zublasing)

"Stress caused by cold is an environmental influence which has a direct effect on the growth and yield of plants", says plant molecular biologist Professor Brigitte Poppenberger. With her research group at the Biotechnology of Horticultural Crops institute at the TUM, she investigates the mechanisms used by plants to adapt to external influences. Her research activities have centered on brassinosteroids for quite some time.

In earlier work, her group already used common thale cress (Arabidopsis thaliana) as a model plant to demonstrate exactly how this plant hormone, which was identified for the first time in rapeseed in 1979, promotes plant growth. In fact, it had been known for a long time that this hormone plays a role in plant development. However, the exact mechanism of action was unknown. It was the work of the biotechnology experts at the TUM School for Life Sciences in Weihenstephan that first made it possible to gain a precise understanding of this phenomenon.

It's no coincidence that Brigitte Poppenbergers team once again picked Arabidopsis for the current study. Due to its relatively undemanding nature, simple structure, and its compact size, it isn't simply a favorite among geneticists in general—the tiny herb also provides optimal conditions under which to search for cold protection mechanisms in plants, as it's able to survive low temperatures and increase its tolerance to frost by adapting to the cold. In the current issue of the specialist journal "Proceedings of the National Academy of Sciences" (PNAS), the scientists describe the hitherto unknown side of brassinosteroids, which up until now have been known as growth hormones.

In order to gain a detailed understanding of their mechanisms, the researchers carried out experiments in which they exposed Arabidopsis plants to slowly decreasing temperatures. Experiments with wild-type varieties in the laboratory showed that as the temperature decreases, the plant reacts by beginning to modify the expression of genes for which DNA is transcribed to RNA within its cells. "This reduces its growth, which increases its chances of survival", Poppenberger explains, describing the natural protective mechanism of the normal plants.

A molecular path to 'winter fat'

The researchers obtained a different result with their experiments involving genetically modified model plants, which are no longer able to synthesize brassinosteroids themselves or recognize them as a signal. While wild-type varieties often still managed to survive temperatures of six degrees below zero, most of the mutants already displayed clear signs of damage at this point, which demonstrates the essential role steroid hormones play in this process. By analyzing the process, the researchers found that brassinosteroids increase frost resistance by regulating a protein called CESTA. This protein uses a signal cascade to control gene expression. In this manner, it in turn influences the protein composition of the cells, which among other things appears to lead to a change in the fatty acid composition. This ensures that the plant stocks up on a type of 'winter fat' on a molecular level, thereby protecting it from potential cold damage.

Spray-on steroids for plants

These exact findings regarding the order and type of chemical processes for the effects of steroid hormones in plants are not only an important step forward for basic research into the adaptation strategies of plants. More importantly, according to the researchers, they may also provide solutions to problems, which have occurred in agriculture as a result of climate change. Although people generally only associate global warming with an increased occurrence of hot periods, it also causes an increase in the number of frost events, such as early and late frosts, which can lead to devastating harvest shortfalls. "The conventional method of breeding more resistant plants has not been very successful so far, as resistance to cold and reduced growth are difficult to separate", says Brigitte Poppenberger. But she's convinced that "our discovery that brassinosteroids boost both growth and cold resistance will open up new possibilities for bringing out both characteristics in plants." She asserts that it's also possible to spray crop plants with brassinosteroids to achieve both effects. "That may be a viable method—at least, that's what the findings suggest."

Publication:
Marina Eremina , Simon J. Unterholzner, Ajith I. Rathnayake , Marcos Castellanos , Sean T. May, Klaus F. X. Mayer, Wilfried Rozhon and Brigitte Poppenberger: Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants, PNAS 2016. doi: 10.1073/pnas.1611477113

Contact:
Technical University of Munich
Biotechnology of Horticultural Crops
Prof. Dr. Brigitte Poppenberger
Tel.: +49 8161 71-2401
brigitte.poppenberger@wzw.tum.de
http://www.bgk.wzw.tum.de/index.php?id=2&L=1

Weitere Informationen:

https://www.tum.de/en/about-tum/news/press-releases/short/article/33364/

Dr. Ulrich Marsch | Technische Universität München

Further reports about: Arabidopsis Horticultural PNAS TUM hormones steroid hormones tolerance

More articles from Life Sciences:

nachricht Lethal combination: Drug cocktail turns off the juice to cancer cells
12.12.2018 | Universität Basel

nachricht Smelling the forest – not the trees
12.12.2018 | Universität Konstanz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New discoveries predict ability to forecast dementia from single molecule

12.12.2018 | Health and Medicine

CCNY-Yale researchers make shape shifting cell breakthrough

12.12.2018 | Physics and Astronomy

Pain: Perception and motor impulses arise in the brain independently of one another

12.12.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>