Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant Hormone Regulates Nectar Production

29.03.2010
Jasmonic acid triggers nectar accumulation in rapeseed flowers

Rapeseed is one of the ten most important agricultural crops worldwide. In spring, the rapeseed fields with their bright yellow flowers are widely visible: this year winter rapeseed is being cultivated on 1.46 million hectares in Germany; at least 2.2 million tons of rapeseed oil can be expected.

Beekeepers set up their beehives in the vicinity of rapeseed fields, so that the worker bees can gather nectar This ensures that the rapeseed flowers are pollinated and a high crop yield will be obtained. During her studies, a scientist from the Max Planck Institute for Chemical Ecology has discovered that the plant hormone jasmonic acid - known as a signalling molecule after herbivory - not only regulates flower development in the bud stage, but also triggers nectar production. (PLoS ONE 5, e9265, 2010 - open access)

Jasmonic acid and related molecules are constituents of molecular signal transduction chains in plant tissues. These compounds - generally referred to as jasmonates - are synthesized when caterpillars feed on plants; they are signaling substances and belong to the group of plant hormones. By producing jasmonates the plant regulates its defense against herbivores e.g. by stimulating the synthesis of toxins. Moreover, previous studies have shown that jasmonates regulate the production of "extrafloral nectar". This particular nectar, which is produced by special glands called "extrafloral nectaries", has nothing to do with pollination, but attracts ants to the herbivore-attacked plants as defenders against their pests. The sugars in the nectar reward the ants for defending the plant. The same principle applies to floral nectar: nectar production in the flowers attracts and rewards pollinators which in turn contribute substantially to the seed yield. However, up to now, it has not been clear how nectar production is regulated in the flowers.

Different effects in flowers and leaves
Radhika Venkatesan, PhD student at the International Max Planck Research School in Jena, studied Brassica napus, a widespread and agriculturally important plant species. She found that when its flower tissues produced jasmonates during an early developmental stage, nectar production was immediately activated, regardless of whether the plant had been attacked by herbivores or not. "When we put caterpillars on the rapeseed leaves to elicit jasmonic acid production, the nectar secretion of the flowers was not affected," the researcher says. Spraying jasmonic acid on the green leaves also did not have an impact on the production of nectar in the flowers. However, when the scientist sprayed jasmonic acid directly on the flowers, nectar production increased dramatically. This clearly indicates that jasmonic acid has different functions in the different plant tissues: whereas the hormone activates defense mechanisms against herbivores in the leaves and the shoot of the plant, it regulates nectar production in the flower tissue.

The correlation between the production of jasmonic acid and nectar accumulation was demonstrated in experiments with an inhibitor: if the flowers had been treated with an inhibitor of jasmonic acid synthesis, the so-called phenidone, nectar production failed. If the substance was sprayed on young, still closed flower buds, however, their opening was inhibited, which confirms the importance of jasmonic acid also during the development of the flowers.

"The fact that jasmonic acid regulates so many functions, such as plant defense and pollination, is extremely interesting and raises new questions, especially concerning the evolution of these control mechanisms," says Martin Heil, the leader of the study. Wilhelm Boland, director at the Max Planck Institute in Jena, emphasizes: "The more we know about the hormonal effects on flower development and nectar production in agricultural crops like rapeseed, the better we can use this knowledge to ensure high yields." Even beekeepers could benefit from increased nectar production. [JWK, AO]

Original Publication:
Venkatesan Radhika, Christian Kost, Wilhelm Boland, Martin Heil: The role of jasmonates in floral nectar secretion. PLoS ONE 5, e9265, 2010 (open access).
Further information:
Prof. Wilhelm Boland, MPI chemische Ökologie, Tel.: 03641 / 57 - 1200, boland@ice.mpg.de

Prof. Martin Heil, CINVESTAV, Irapuato, Mexiko, Tel.: +52 (462)623 9657, mheil@ira.cinvestav.mx

Picture Material:
Angela Overmeyer M.A., MPI for Chemical Ecology, Tel.: 03641 / 57-2110, overmeyer@ice.mpg.de

Dr. Jan-Wolfhard Kellmann | Max-Planck-Institut
Further information:
http://www.ice.mpg.de

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>