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 Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?
26.05.2017 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

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

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

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

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>