Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dwarf mistletoe reveals its sexual secrets

15.12.2004


Hold off putting up your usual variety of mistletoe – the dwarf mistletoe could soon eclipse its better-known Christmas cousins as the green fertility symbol of choice for holiday party goers. In fact, the discovery of the intimate details of the sex life of the dwarf mistletoe is even getting traditionally staid botanists hot and bothered.

New research shows that the dwarf mistletoe, a member of the same Viscaceae family as the better-known Christmas varieties, is truly worthy of being hung with pride. The stubby variety might be a clumpy green parasite of conifers, but it turns out to have the world’s only water-pump seed ejection system. One that can fire a seed up to a dazzling 20 meters (65 feet). So who are you calling a dwarf now?

"The dwarf species I studied in Manitoba has a gestation period of one-and-a-half years, after which the seed blasts out of the fruit. This extreme buildup of water pressure as a seed dispersal system is rare in the plant world," says Dr. Cynthia Ross, an assistant professor at the University College of the Cariboo in Kamloops, British Columbia.



Dr. Ross, who describes herself as a "plant gynecologist," is the first to figure out some of the cellular characteristics behind the dwarf mistletoe’s impressive ejection system. The results of her NSERC-funded research, co-authored by the University of Manitoba’s Dr. Michael J. Sumner, are published, in part, in the current issue of the Canadian Journal of Botany.

The seeds of the larger Christmas mistletoes (Viscum album and Phoradendron serotinum, parasites respectively of trees in Europe and the eastern U.S.) are dispersed by birds. Indeed, "mistletoe" literally means "turd on a twig." This refers to the fact that offspring of these parasitic plants start to grow on a new tree host after being eaten and deposited by a bird, complete with their own kick-start fertilizer.

But the dwarf mistletoe takes spreading its seed into its own hands. Through a painstaking microscopic analysis of the seed’s embryonic development, Dr. Ross determined that the growing fruit stores water in a gelatinous substance secreted by helical, or spring-shaped, cells. The water pressure builds until, aided by the spring-like nature of the cells, the fruit explodes.

In Manitoba this mass birthing event occurs during a two-day period around Labour Day. (Really.) "It’s an event that takes place very quickly," says Dr. Ross of the ejection of the rice-grain-sized seeds. "I’ve been hit by them." As if this discovery weren’t enough to earn the dwarf mistletoe a place of honour by the front door, Dr. Ross says her probing has revealed another floral first that’s "really going to shake things up" in the world of plant reproduction science.

The male portion of the dwarf mistletoe sends out its pollen tube prematurely (or pre-emptively, depending on your interpretation). "In all previously described flowering plants, the formation of the egg and its accessory cells is thought to trigger a chemical signal that causes the pollen tube to find the egg and fertilize it. But with my dwarf mistletoe, the pollen tube, which contains the plant’s sperm, grows down through the young flower and reaches the area where the egg is going to be long before the egg develops. And that contradicts all of the previous literature," explains Dr. Ross.

Understanding the details of the dwarf mistletoe’s bedroom life feeds more than just verdant curiosity. Dwarf mistletoes (species of the genus Arceuthobium) are the most destructive pathogens of standing timber in North America. These parasites suck water, minerals and sugars from their tree hosts, stunting their growth and in some cases killing the trees. These include economically important trees, such as the lodgepole pine in British Columbia and the jack pine in central Canada.

"We could potentially target the unusual characteristics of dwarf mistletoe reproduction in disease control, either at the pollination or seed dispersal stages," says Dr. Ross. "Neighbouring plants, thanks to their more mundane sex life, would likely be safe from whatever we use to kill the pathogen."

Mistletoe’s association with sacred winter celebrations, fertility and kissing is an ancient one, extending back into pre-Christian Europe. The European mistletoe parasitizes apple and oak trees and thus in winter stands out in brilliant green against its leafless hosts. This evergreen nature, and the fact that the plant seems to emerge seedless from bird dung, prompted ancient peoples’ regard for it as a symbol of fertility, endurance and strength.

Cythia Ross | EurekAlert!
Further information:
http://www.cariboo.bc.ca
http://www.nserc.ca

More articles from Life Sciences:

nachricht Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)

nachricht CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>