Navigation Links
New moth variety disarms plants guarded by selenium

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.

Source:Cell Press

Related biology news :

1. Fitting in: Newly evolved genes adopt a variety of strategies to remain in the gene pool
2. Researchers release new variety of asparagus
3. Inflammation and drugs to control this activity studied in a variety of tumors sites
4. Emory Eye Center Implants Its First Retinal Chips In Patients With Retinitis Pigmentosa
5. Antibodies from plants protect against anthrax
6. New RNA polymerase discovered in plants
7. Transgenic plants remove more selenium from polluted soil than wild plants, new tests show
8. Scientists discover how plants disarm the toxic effects of excessive sunlight
9. Defenseless plants arm themselves with metals
10. At long last, scientists figure out how plants grow
11. Precise Timing Enabled Pig-to-rat Transplants To Cure Diabetes

Post Your Comments:

(Date:11/9/2015)... 2015 ... "Global Law Enforcement Biometrics Market 2015-2019" ... ) has announced the addition ... Market 2015-2019" report to their offering. ... ) has announced the addition of ...
(Date:11/2/2015)... Calif. , Nov. 2, 2015  SRI International ... million to provide preclinical development services to the National ... contract, SRI will provide scientific expertise, modern testing and ... variety of preclinical pharmacology and toxicology studies to evaluate ... --> The PREVENT Cancer Drug Development Program ...
(Date:10/29/2015)... 2015 Daon, a global leader in mobile ... a new version of its IdentityX Platform , ... America have already installed IdentityX v4.0 and ... FIDO UAF certified server component as an ... FIDO features. These customers include some of the largest ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... , November 25, 2015 ... Report is a professional and in-depth study on ...      (Logo: ) , ... the industry including definitions, classifications, applications and industry ... for the international markets including development trends, competitive ...
(Date:11/24/2015)... , Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: ... in New York on Wednesday, December 2 ... Torley , president and CEO, will provide a corporate overview. ... York at 1:00 p.m. ET/10:00 a.m. PT . ... relations, will provide a corporate overview. --> th ...
(Date:11/24/2015)... -- Clintrax Global, Inc., a worldwide provider of clinical research services headquartered ... the company has set a new quarterly earnings record in Q3 ... posted for Q3 of 2014 to Q3 of 2015.   ... , with the establishment of an Asia-Pacific ... United Kingdom and Mexico , with ...
(Date:11/24/2015)... 2015 --> ... released by Transparency Market Research, the global non-invasive prenatal ... of 17.5% during the period between 2014 and 2022. ... Industry Analysis, Size, Volume, Share, Growth, Trends and Forecast ... market to reach a valuation of US$2.38 bn by ...
Breaking Biology Technology: