greenseedling

Salt bad for plants, people, say scientists

Seorin — Fri, 06 Apr 2012 13:48:04 +0000

Salty soil can kill crops. In fact, salinity cripples roughly one-fifth of all arable land worldwide. To mitigate salt’s influence on crops, farmers have had to outwit their saline nemesis by adapting agriculture to less hospitable environments, whose soils are highly salty.

Consider durum wheat, a major staple of the human diet. Excessive amounts of sodium in the soil interfere with the plant’s ability to photosynthesize. As a result, the strain produces a much lower yield in salty but arable land. This was not always the case. Ancestral strains of the wheat were able to withstand such conditions. It was only through thousands of years of selective crossing and hybridization that durum lost its impervious, hardy health.

But researchers in Australia have now identified a salt-tolerant gene (mHKT1;5-A) that, when included in the genome of the durum wheat plant, can block the salt from preventing photosynthesis. How? The gene simply refuses to grant sodium access to the inner workings of the plant’s leaves.

The solution is simple, but its effects are dramatic. In a series of experiments, scientists found that the salt-tolerant gene had no effect on crop yield when plants were grown in soil without salt. However, when grown in salty soil, the crop yield of plants with the salt-tolerant gene was greater than the yields of plants without the gene by as much as 25%. Because there is no effect on yield in soil without salt, farmers would not need to keep two different types of crops depending on soil type: they could potentially grow the salt-tolerant version of the plants in either environment—salty or not.

Implementing the solution, therefore, would not require any special knowledge or labor. Like the wheat itself–durable, elegant, modest, and meet–the answer may go a long way, on a little effort, toward serving our biological habits.
Discussion Question: What other soil conditions can affect crop yields?

News Article: http://www.sciencedaily.com/releases/2012/03/120311150717.htm
Journal Article: http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.2120.html

Image Source: http://en.wikipedia.org/wiki/File:Wheat_P1210892.jpg

Mutated Plants Ease Cellulose Sugar Conversion

Surabhi — Thu, 05 Apr 2012 13:53:29 +0000

In Genetics, we learn how mutations can cause deletion or the over expression of specific genes. Mutations can be very beneficial. For example, an advantageous mutation in plants was discovered that improves the cellulosic biofuel procedure.

Cellulose’s crystal structure makes it very hard to break cellulose down into sugars. To find a solution to this problem, Professor Debolt at the University of Kentucky and colleagues tested genetic mutations that produced cellulose with reduced crystal structure. Team members, associate of the U.S. Department of Energy, Mei Hong, and graduate student Tuo Wang used solid-state nuclear magnetic resonance spectroscopy to study the mutated cell walls.

Hong and Wang found that the mutated cell walls did in fact have less crystalline cellulose. The researchers observed that the cellulose microfibrils in the mutant cell walls were thinner than non-mutant plants. When compared with regular plants, the mutated plants converted cellulose into sugars (which are fermented into alcohol for biofuel) more efficiently.

This study suggests that manipulation of plant structure may be the key to more economical biofuels. The research project, funded by the National Science Foundation and the U.S. Department of Energy, hopes to develop more methods that manipulate crop-cellulose to ease its conversion into sugars.

Discussion Question: How could the plant mutations impact the plant negatively? Would it decrease the plant’s durability or growth?

News Article: http://www.sciencedaily.com/releases/2012/02/120228152158.htm
Press Release: http://www.news.iastate.edu/news/2012/feb/cellulose

Image: http://morgellonswatch.com

Natural Doesn’t Always Mean Healthy

Tejasvi — Wed, 04 Apr 2012 13:41:16 +0000

In recent years, the consumption of “natural” dietary supplements has increased significantly. People tend to associate the word “natural” with healthy. However, new research at the Wageningen University on plant based supplements explored what the supplements actually contain. It was discovered that the supplements contain alkenylbenzenes, which are compounds that have been known to cause liver cancer in animal studies. This study concluded that although dietary supplements do not contain the high levels of alkenylbenzenes, it is important to raise awareness about the presence of harmful compounds in the supplements.

In the European Union, the popularity of dietary supplements is incredibly high and has caused the EU to produce standards on which plant based compounds are safe to use. They have already banned certain types of alkenylbenzenes from being used as food-flavoring agents but many can still be used in supplements.

Furthermore, analysis of supplements containing nutmeg, basil, fennel and other such spices has revealed that they contain very high concentrations of alkenylbenzenes. The use of these plants is not under heavy regulation and their presence usually makes the supplement seem more natural and healthy.

The research group does not claim that their findings should cause widespread alarm since they stress that the concentration of alkenylbenzenes in the food supplements is not significant. However, they hope to continue their research by focusing on how the presence of other ingredients minimizes the cancerous effects of alkenylbenzenes.

Discussion Question: How does the marketing of these products to the general public achieve the perception of being ‘healthy’? Do these studies cause unnecessary alarm in the public when there is no significant threat caused by the low concentrations of alkenylbenzenes?

News Article: http://www.sciencedaily.com/releases/2011/12/111212123652.htm
Journal Article: http://www.wur.nl/UK/newsagenda/news/P097_PlantFoodSupplements_.htm

Image: http://www.healblog.net/wp-content/uploads/diet-supplement2.jpg

How Bugs Learned to Eat Poison and Like it

Seorin — Tue, 03 Apr 2012 13:28:14 +0000

In the evolutionary arms race between plants and herbivores, plants continuously develop chemical defenses against the herbivores who would steal their nutrients, and the herbivores in turn continuously develop counter-defenses to those chemical toxins. In a remarkable evolutionary twist, certain insects, such as the African variegated grasshopper, have not only developed a counter-defense to chemical plant toxins but have also developed a way to use those toxins in their own defense against predators.

Scientists report that the key deadly ingredients are pyrrolizidine alkaloids found in ragwort. Herbivores lacking appropriate counter-defenses suffer no ill effects upon initial consumption of the alkaloids but later succumb when their digestive systems render toxins from the alkaloids. The African grasshopper, however, has developed an enzyme that converts those very toxins back into their original benign states. Thus, the grasshopper not only safely obtains nutrition from the ragwort, it also carries the alkaloids in its body for use as a chemical defense against any animals that may predate upon it.

Interestingly, the African grasshopper is not the only insect to have developed an enzymatic defense against alkaloids. The cinnabar moth also possesses a similar enzyme that allows it to keep alkaloids safely within its body as a defense against predation. As Professor Dietrich Ober remarks, “[t]he most exciting aspect of this finding” is that this discovery is an example of convergent evolution, a process by which two completely different species develop similar adaptations due to similar niches.

Because the grasshoppers are drawn to alkaloids for their own chemical defenses, Professor Ober suggests that alkaloids could be used to lure and capture grasshoppers. In this way, perhaps humans interested in managing agricultural pests can use insects’ own counter-defenses against them.

Discussion Question: What are some other examples of convergent evolution?

News Article: http://www.sciencedaily.com/releases/2012/02/120221090240.htm
Journal Article: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031796
Image Source: http://en.wikipedia.org/wiki/File:Golden_Ragwort_Senecio_aureus_Plant_3264px.JPG

‘Mini-Cellulose’, One Huge Discovery for Biofuels

Surabhi — Mon, 02 Apr 2012 14:22:25 +0000

Professor Dauenhauer and his team of chemical engineers at the University of Massachusetts Amherst have discovered a ‘mini-cellulose molecule’ called α-cyclodextrin that behaves similar to cellulose during biofuel production. Engineers hope to use this molecule to study the chemical reactions in the high-temperature biofuel processes of wood and grass, as well as create a computer simulation of biomass, thereby improving the biofuel-making process.

Due to unknown complex chemical reactions in wood during the biofuel-making process, engineers estimated that it could take a thousand years to simulate chemical reactions using real cellulose. With the ‘mini-cellulose’, researchers will be able to cut down the time it takes to simulate chemical reactions to only one month! The simulations will give details of the chemical reactions that occur in wood conversions. Scientists will then use the reactions to help reduce carbon emissions in biofuel-making process and design furans, molecules that are essential in biofuel production.

‘Mini-cellulose’ has also led to many new experimental discoveries including “thin-film pryolysis.” This process involves heating constructed sheets of cellulose, which are only a few microns in width, at over a million degrees Celsius per minute. This results in volatile chemicals that are precursors of biofuel.

With so many advantages of using ‘mini-cellulose’, it is no surprise that Dauenhauer and his team have won prestigious grants to expand their research. There are sure to be many more significant discoveries to look forward to from this team.

Discussion Question: Could the ‘mini-cellulose’ help make the biofuels more marketable and cost-efficient? Explain why or why not.

News Article: http://www.sciencedaily.com/releases/2012/02/120216165757.htm
Press Release: http://www.umass.edu/loop/talkingpoints/articles/147031.php

Image: http://images.sciencedaily.com/2012/02/120216165757.jpg

Plants “smell” disease and make themselves resistant

Seorin — Fri, 30 Mar 2012 14:20:00 +0000

For two decades, biologists have been aware of a curious phenomenon: trees in proximity can communicate chemically with one another. In fact, as a result of the communication between diseased or distressed trees and nearby healthy trees, healthy trees respond by increasing their defenses against the disease that plagues their neighbors. Although trees that communicate in this fashion are often referred to as “talking trees,” the message from distressed trees is not communicated by sound. Rather, the message is relayed via odor, and healthy trees receive the message, in a sense, by “smelling.

How much time and how much of an odor is required in order to induce a defensive response in nearby plants? In order to answer this question, a recent experiment from CINESTAV-Irapuato examines this inter-plant communication process in lima beans by exposing the plants to two different odors, or volatile organic compounds (VOCs): (1) nonanal and (2) methyl salicylate (MeSA).

The researchers found that, after six hours of exposure to nonanal, the plants had an increased resistance to bacterial infection caused by Pseudomonas syringae. This was also true after 24 hours of exposure, and the amount of the volatile present had no significant effect on resistance of nearby plants.

When the plants were exposed to MeSA, six hours of exposure was insufficient to induce a significant resistance to bacterial infection. After 24 hours of exposure, however, the plants exhibited a marked increase in resistance. As with nonanal, the level of concentration of MeSA appeared to have no significant effect in the plants’ resistance.
Discussion Question: Describe other chemical means by which organisms can communicate.

News Article: http://www.sciencedaily.com/releases/2012/03/120305081256.htm
Journal Article: http://www.springerlink.com/content/g1221k4318151085/

Image Source: http://en.wikipedia.org/wiki/File:Lima_beans.jpg

Tobacco Leaves Produce Biofuel

Surabhi — Thu, 29 Mar 2012 14:01:09 +0000

Who knew tobacco, a plant most widely known to be used in cigarettes, could also be a fuel source? Tobacco’s compatibility with genetic engineering, large leaves, and ability to harvest multiple times in a year, make it a great bioenergy source. Researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory are trying to engineer tobacco plants to produce fuel molecules directly in their leaves. This $4.9 million project is led by Christer Jansson and funded by DOE’s Advanced Research Projects Agency-Energy (ARPA-E).

Jansson and his team aim to cut many steps in the present biofuel production method. The team hopes to do this by creating tobacco plants that take in and hold carbon dioxide from the air and converts the carbon into fuel that is almost ready to be used. The final fuel is made by crushing the biomass, and then shortening the extracted hydrocarbon molecules into usable fuels like gasoline and diesel.

In the future, Jansson plans to synthesize cyanobacteria genes that encode hydrocarbon producing enzymes. These genes will be placed in tobacco plants and their leaves will be imaged via nuclear magnetic resonance to find ways to improve their metabolic engineering. Increasing the carbon dioxide uptake by tobacco will also increase the amount of hydrocarbons in the plant.

The final goal is to grow tobacco plants in which 20% to 30% of their dry-weight will be hydrocarbons. Scientists plan to grow their first engineered tobacco plant in approximately 17 months.

Discussion Question: Tobacco is viewed as a negative substance by many people because of its presence in cigarettes. Could this perception impact how people view tobacco biofuel? If tobacco biofuel is mass-produced, could the positive aspects change people’s view of tobacco?

News Article: http://www.physorg.com/news/2012-02-er-tobacco-berkeley-lab-led-team.html
Press Release: http://newscenter.lbl.gov/feature-stories/2012/02/23/tobacco-biofuels/

Image: http://en.wikipedia.org/wiki/File:Nicotiana_Tobacco_Plants_1909px.jpg

African Tribal Tea Reveals Amazing Proteins

Tejasvi — Wed, 28 Mar 2012 14:30:55 +0000

The family of proteins called cyclotides are small circular polypeptides that are incredibly stable even at very high temperatures. The cyclopeptides are the prime interest of Marilyn Anderson of LaTrobe University, Australia who conducts research on the genetics of this class of proteins.

Cyclotides were discovered through investigation of an African tribal tea used to induce childbirth. They are commonly found in the plant families of Rubiacea, Violacae, Cucurbitaceae and Fabaceae. Linear cyclotides with similar functions are found in more common plants such as rice, corn and barley. African tribes boil the leaves that contain these cyclotides and are able to draw them into the tea. When ingested, the cyclotides enter the small intestine and travel into the uterus once absorbed by the bloodstream. This tea is called kalata kalata and is brewed from the leaves of Oldenlandia affinis.

Not only do these cyclotides have the surprising ability to induce childbirth, they can potentially be useful for many other health issues. When found naturally in plants, it serves as a great insecticidal and nematocidal. As for humans, the cyclotides’ benefits range from antimicrobial to anti-HIV properties.

Discussion Questions: Would drinking this natural tea have the same effects as if the proteins were able to be manufactured into pills? Are natural remedies safer?

News Article: http://news.biocompare.com/News/NewsStory/406794/Cellular-Processing-Of-Proteins-Found-In-Congolese-Child-Birthing-Tea-Now-Revealed.html

Research Article: http://www.amjbot.org/content/98/12/2018.full.pdf+html

Photo: http://www.zimbabweflora.co.zw/speciesdata/images/15/154850-4.jpg

New Research Makes Seaweed a Leading Candidate for Nonrenewable Energy

Surabhi — Mon, 26 Mar 2012 14:26:41 +0000

In previous articles, we have discussed the positive aspects of using seaweed as a biofuel source. New research by Professor Abelson and his team at Tel Aviv University are developing methods to grow and harvest seaweed in ways that may reduce marine-ecosystem pollution caused by humans.

Coastal regions such as the Red Sea are damaged by human waste and mass fishing. This leads to excessive nutrients in the water known as eutrophication, which favors algae growth but harms coral reefs. Keeping this in mind, researchers are creating a “human-made ecosystem” that uses the “Combined Aquaculture Multi-Use System” (CAMUS). CAMUS factors in marine environment as well as human activity. Essentially, CAMUS will be able to reduce the harmful human environmental impact by using water-filtered pollution particles to sustain vast amount of seaweed for fuel conversion.

With the CAMUS system, scientists hope to covert seaweed into bioethanol at low-cost and in a highly productive manner. Currently, the researchers are trying to increase the carbohydrate and sugar components of seaweed in order to ferment seaweed more effectively.

Discussion Question: How would clearing water of excessive nutrients change the marine-ecosystem and land-ecosystem?

News Article: http://www.sciencedaily.com/releases/2012/03/120305132534.htm
Press Release: http://www.aftau.org/site/News2?page=NewsArticle&id=16111

Image: http://en.wikipedia.org

Berry Fruits as Brain Fuel

Christina — Mon, 26 Mar 2012 14:11:27 +0000

When I grew up, the only kind of blackberry I knew was the fruit (not the cellular device), but I never knew that blackberries were extremely beneficial to the human body. In a study in ACS’ Journal of Agricultural and Food Chemistry, scientists discuss the benefit of consuming various berry fruits. Strawberries, blueberries, and blackberries can affect certain processers in the brain, reducing memory loss and other issues related to aging.

Researchers discovered that antioxidants—complexes that protect cells from damage—are plentiful in berry fruits. In addition, berry fruits have the potential to alter neuron communication in the brain, avoiding brain inflammation that could potentially cause damage to the neurons. Strawberries, blackberries, and blueberries can also enhance motor control and thinking, which would explain why these fruits help to prevent memory loss.

Do all berries have this potential to affect the brain? Scientists don’t know yet. Meanwhile, I’m going to make sure to include a few servings of berries in my meals!

Discussion question: Do you think other fruits are able to prevent memory loss? What possible components in the fruits could make this be possible?

Article source: http://www.sciencedaily.com/releases/2012/03/120307145825.htm
Journal source: http://pubs.acs.org/doi/abs/10.1021/jf2036033

Image source: http://commons.wikimedia.org/wiki/File:Blueberries-Littleisland.jpg