Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New mechanisms uncovered explaining frost tolerance in plants


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."

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

Technical University of Munich
Biotechnology of Horticultural Crops
Prof. Dr. Brigitte Poppenberger
Tel.: +49 8161 71-2401

Weitere Informationen:

Dr. Ulrich Marsch | Technische Universität München

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

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>