Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New moth variety disarms plants guarded by selenium

21.11.2006
In new work, researchers report that the ability of plants to defend themselves by accumulating high levels of a toxic element can be overcome by some insects, and that such adaptation potentially echoes in the food web as other predators and parasites may in turn evolve to deal with high levels of the toxic element.

The findings, reported by Elizabeth Pilon-Smits of Colorado State University and colleagues there and at the University of California, Berkeley, appear in the November 21st issue of the journal Current Biology, published by Cell Press.

Some plants "hyperaccumulate" the element selenium to extreme levels--up to 1% of the plant's dry weight. Selenium, an element with properties similar to sulfur, is an essential trace element for many organisms, but it typically is toxic at high levels, and the function behind the intriguing tendency of some plants to hyperaccumulate this element has been largely obscure. The so-called elemental-defense hypothesis proposes that hyperaccumulated elements serve a defensive function against herbivory, the predation of plants by animals.

In their new work, the researchers showed that the selenium in the hyperaccumulator plant species known as prince's plume (Stanleya pinnata) protects it from caterpillar herbivory both by deterring feeding and by causing toxicity in the caterpillar. However, the researchers also showed that in the plant's natural habitat, a newly discovered variety of the invasive diamondback moth (Plutella xylostella) has disarmed the plant's elemental defense. The new moth variety in fact thrives on plants containing highly toxic selenium levels and, in contrast to related varieties, was not deterred from either laying eggs or feeding on the plant. Furthermore, the researchers found that a selenium-tolerant wasp (Diadegma insulare) in turn parasitizes the selenium-tolerant diamondback moth.

Chemical analysis showed that the selenium-tolerant moth and its parasite both accumulate selenium in the form of methylselenocysteine, the same form found in the hyperaccumulator plant, whereas related but selenium-sensitive moths accumulate selenium as selenocysteine. The latter form is toxic because of its ability to be incorporated into proteins.

The authors outline a possible course of events in the evolution of selenium tolerance in the newly discovered diamondback moth. Their overall conclusion is that although selenium hyperaccumulation protects plants from herbivory by some invertebrates, it can give rise to the evolution of unique selenium-tolerant herbivores, thereby providing a "portal" for selenium into the local ecosystem--that is, a pathway by which selenium hyperaccumulation may spread within parts of the food web.

The authors point out that in a broader context, the findings potentially have implications for a number of ways in which selenium accumulation might be utilized in different ecological and agricultural circumstances. Applying selenium to plants may be an efficient way to deter herbivory and improve crop productivity, and if managed carefully, the supplied selenium could give added value to the crop (some evidence suggests that selenium has anticarcinogenic properties). Furthermore, the newly discovered selenium-tolerant moth may be used for biological control of plants that hyperaccumulate selenium in areas where such plants cause poisoning of livestock. In addition, the selenium-hyperaccumulator plant may also be useful for removing and dispersing selenium from polluted water and soil. The authors note that such use of native selenium hyperaccumulators or of selenium-enriched agricultural crops--for environmental cleanup or as a source of anti-carcinogenic selenocompounds--may have ecological implications, as is clear from the apparent rapid evolution of selenium-tolerant insects shown in this study.

Heidi Hardman | EurekAlert!
Further information:
http://www.current-biology.com

Further reports about: herbivory moth selenium selenium-tolerant toxic variety

More articles from Life Sciences:

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>