Bt-maize, the genetically modified crop, is commonly used in the field because it is resistant to certain insects. The group of scientists tested the Bt crop’s effects on pigs over the short term (31 days), longer term (110 days) and over generations. Scientists fed the piglets Bt-maize and recorded the increasing or declining health of the pigs. The initial results from the study suggest pigs of all ages can safely consume Bt-maize with no detrimental effects.

While it is true that humans and pigs differ, the researchers of the experiment believe that this should provide some comfort to individuals who consume genetically modified corn. Certainly, Bt-maize is not the only genetically modified product on the market, and scientists are hoping to conduct further experiments in order to strengthen their studies on other modified foods.

For now, this study suggests that Bt-maize is safe to consume.

Discussion question: While pigs and humans do have similar gastrointestinal tracts, why might it be premature to conclude that genetically modified Bt-maize is perfectly safe for people to consume?

Article source: http://www.sciencedaily.com/releases/2012/01/120124140103.htm

Journal source: http://www.teagasc.ie/news/2012/201201-24a.asp
Image source: http://commons.wikimedia.org/wiki/File:Corn_01.JPG

Recently, scientists have struck back against one pest in particular, the Princeps (Papilio)  demoleus, a caterpillar with a taste for limes, and they have done so without the use of traditional pesticides or poisons.  Instead, using research first pioneered back in 1998 by Bruce Stevens and his colleagues at the University of Florida, they are exploring a green alternative that disrupt the insect’s ion channel, blocking its nutrient absorption and starving it.

What is the miracle “pesticide”? An amino acid. Methionine, which humans cannot live without, kills the larvae of the Citrus Swallowtail, as well as any invasive larvae with an alkaline intestine. Because it is not toxic to humans, mammals, or birds, or to the citrus it coats, methionine offers an environmentally friendly alternative to conventional pesticides, which are noxious to bugs and humans alike. Furthermore, because the amino acid is a biodegradable nitrogen source, if it reaches the ground it can serve as a cheap fertilizer for the very plant it protects.
Unfortunately, because the Citrus Swallowtail is invasive, researchers cannot test their amino acid defense against it directly, as bringing it into the country would violate laws regulating the import of dangerous species. In its place they have substituted the Heraclides (Papilio) cresphontes, or Giant Swallowtail. Because of its close genetic relationship to the Lime Swallowtail, as well as its similar appetite, digestive tract, and morphology, the insect has been pressed into service as a surrogate for its unlawful cousin.

Experiments conducted at the University of Florida have demonstrated that the methionine pesticide is 100 percent effective against Giant Swallowtails, killing all targeted larvae in no more than 72 hours. And because the Lime Swallowtail has not yet reached Floridian shores—at present it dwells in the Caribbean—the citrus industry, which the insect potentially could devastate, can be confident that when the invader comes, as they all eventually do, scientists will meet it with a fresh crop of tainted limes. The bugs will dine once on the delicious fruit, and then never again.

Discussion Question: Compare and contrast the advantages and disadvantages of using traditional pesticides as opposed to methionine to protect lime trees.

News Article: http://www.sciencedaily.com/releases/2012/01/120117145101.htm
Journal Article: http://www.bioone.org/doi/abs/10.1603/EC11132

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

There are, however, “fertilizers” tailored specifically to release phosphorous to plants: fungi, specifically arbuscular mycorrhizal, which furnish plants with the scarce nutrient–for a price. Arbuscular mycorrhizal (AM) fungi and plants share a symbiotic relationship in which both parties benefit. AM fungi, with their long filaments, are efficient and capable collectors of phosphorus, even in nutrient-poor soil, and they willingly trade the phosphorus they absorb with their plant hosts in exchange for sugars, which plants readily manufacture through photosynthesis.

Some details of the symbiosis were already well known to scientists when Franziska Krajinski and her colleagues at the Max Planck Institute began their research on plant-fungi relationships. Certain cells in the plant, for example, manufacture protein complexes through which the phosphorous and sugar molecules move from plant to fungus; in cells colonized by AM fungi, the genes that encode for these proteins are well expressed.

What the team did not expect to find, however, was the reprogramming they discovered in cells adjacent to or even just near the colonization sites. As first author of the study Nicole Gaude explains, by encoding for the transport proteins, these cells “are preparing themselves for an imminent colonization by the fungus.” Cells, then, activate specific genes–those that facilitate the symbiosis–“even before symbiosis is physically established.”

Discussion Question: Describe some ways in which symbiotic relationships can benefit agriculture.

News Article: http://www.sciencedaily.com/releases/2011/11/111114133644.htm
Journal Article: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2011.04810.x/abstract

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

Stem rust, a crop disease, is a new threat to barley and can contribute to the total loss of a farmer’s crop. Scientists initially thought that the disease had to penetrate the plant to instigate resistance, but current research shows that within five minutes of invasion, barley establishes a response system to the intruder and musters its defenses.

Genetic engineering and manipulation are key processes in understanding the plant-pathogen connection. Puccinia graminis 1 (Rpg1), a gene that imparts long-lasting resistance in barley, helps to identify the invading pathogen within minutes of the stem rust spore contacting the leaf. Assistant Research Professor Jayaveeramuthu Nirmala observed this communication process and recorded faint, chemical changes in the plant, demonstrating pathogen recognition and defense initiation.

This clear interaction is a ‘game-changer’ for agronomists. Further studies with barley will give scientists more information on the plant-pathogen relationship, which can then be applied to similar plants.

Discussion Question: Besides pathogen resistance, what are some other defense mechanisms that plants like to utilize?

News article: http://www.sciencedaily.com/releases/2011/10/111013113818.htm
Journal article: http://www.pnas.org/content/108/35/14676

Picture source: http://en.wikipedia.org/wiki/File:Barley.jpg

Enter the corn earworm, bane of American agriculture. This insect costs American farmers approximately two billion dollars each year as it plunders more than one hundred crop species. Given the bug’s generous appetite and propensity for bankrupting businesses, which face the unenviable task of protecting their investments from such capable freeloaders, a team of scientists recently probed the bug’s biology for weaknesses. And they found one: diapause.

Every organism requires energy. Typically we think of this energy as food, but energy also involves immunity, an organism’s power to carry the weight of adverse conditions; to repair the damages wrought by harsh weather or poor diet; to restore the body from a state of weakness. Sleep is vital to health, not only ours but the earworm’s as well. Without it, the insects are likely to perish during the harsh winters, when they usually rest.

Their seasonal sleeping–diapause–works like hibernation. When food is scarce, and the climate hostile, the earworms conserve energy by going into a prolonged restful state. By doing so they avoid environmental threats, slow down their bodies, and bide their time until conditions improve, when food is more plentiful and the ground and air warmer. If the insects were to enter diapause at the wrong time–spring, for example, when they would sleep instead of feed–they would meet the winter weak, hungry, tired–easy prey for the cold. And of course, not sleeping during the seasonal chill, when food is lacking, defeats the whole purpose of hibernating anyway.

How do the earworms know when to sleep and when to wake up? A specific hormone, diapause hormone (DH), triggers dormancy; it also ends it. Realizing its crucial role in the insect’s health, the team focused on manipulating DH. If they could somehow interfere with the hormone’s function in a healthy earworm, they might discover an alternative, and effective, control against infestation, saving farmers and business a significant amount of time, effort, and money, and doing so in style.

Researchers experimented with DH by synthesizing compounds that mimic its structure, in particular the amino acids that give DH its unique profile. Soon they discovered that they could manipulate earworm sleep by waking the insects up too early, keeping them from falling asleep, or inducing permanent sleep, essentially killing them. Like a Trojan horse, the compound tricks its host into recognizing it as the diapause hormone, and from that point, the scientists can control when, how, and for how long the earworm sleeps–or whether it sleeps at all. As researcher David Denlinger explains, it’s “a pretty effective tool.”

Discussion Questions: Are there any organisms that can thrive without sleep? Why or why not?

News Article: http://www.sciencedaily.com/releases/2011/09/110928110014.htm
Journal Article: http://www.pnas.org/content/108/41/16922

Image Source: http://en.wikipedia.org/wiki/File:Corn_Zea_mays_Plant_Row_2000px.jpg

Cacao products, such as the chocolate and powder, come from the cacao beans, which are grown from its evergreen tree, Theobroma cacao. Because of cacao’s global popularity, much research and exploration has been conducted on this plant. Recently, U.S. Department of Agriculture scientists have focused specifically on the cacao trees in the Amazon Basin of Peru.

During the researchers’ expeditions to Peru, leader Lyndel Meinhardt discovered that many wild cacaos trees suffered from witches’ broom, a disease that causes deformations in the leaves, flowers, or trunks of woody plants. This disease is caused by a fungus and is estimated to cause losses of 75% in the yields of cacao. Meinhardt and his team found that a high percentage of cacao varieties were infected with witches’ broom disease, indicating the disease’s resistance amongst the plant population in Peru.

In comparison, the scientists then examined the fungus of the disease-free cacao trees. The scientists believe that these fungi samples that they collected from the tree’s tissue may protect against all sorts of disease, one of them being witches’ broom. They hypothesize that the fungi acts either by stimulating the immune system or through parasitic or antibiotic effects against pathogens.

To further understand this mechanism, a research center has been established in Peru to study and categorize DNA of the different cacao varieties so that biological control can be achieved.

Discussion Question: What environmental factors may contribute to the success and proliferation of the cacao tree in the Amazon area?

News article: http://www.sciencedaily.com/releases/2011/09/110915114002.htm
Information page: http://www.ars.usda.gov/is/AR/archive/sep11/cacao0911.htm

Picture: http://en.wikipedia.org/wiki/File:Matadecacao.jpg

Currently, scientists are conducting studies with different soybean varieties and looking at seed germination in modified phosphorus soybeans versus control soybean plants. One researcher, Dr. Laura Maupin, collected data from soybean crops in twelve different environments and performed an analysis. While there were both high and low phytate-modified crops, her data shows that on average most low phytate-modified soybeans had lower seedling emergence compared to the control soybean plants. This drop in seedling emergence in low phytate plants is actually a result of low vigor seedlings.

Low vigor soybean seedlings with low phytate can be addressed through a multitude of strategies. With so much data from different habitats, researchers believe that techniques like germination assays, markers, multi-environment trials, and elite parents will give us a better understanding on the issue of seed germination in relation to phytate content, resulting in a more nutritious soybean crop.

Discussion Question: What other factors might play a role in seedling emergence of soybean?

News article: http://www.sciencedaily.com/releases/2011/09/110917082732.htm
Journal article: https://www.agronomy.org/
Image source: http://en.wikipedia.org/wiki/Soybean

In agricultural societies such as ours, we strive to maximize efficiency and to reduce waste; on a farm, this tenet typically surfaces in a prejudice against weeds, which, whenever possible, the farmer eliminates. But although weeds don’t benefit the farmer directly, by increasing the yield for that harvest, they do serve a subtler and more venerable purpose. Because they comprise an essential part of the larger ecosystem, which includes the herbivores and pollinators that obtain their nutrients from them, weeds promote the land’s sustainability and, therefore, its future worth to the farmer.

It is important to note that the definition of a weed is an arbitrary one indicating any plant that a farmer or gardener prefers not to grow in a particular plot of land. From an ecological perspective, there is no such thing as a weed. Each plant contributes to biodiversity and plays a vital role in its ecosystem by providing, for example, essential nutrients for pollinating insects–the very pollinating insects on which we depend to pollinate our crops, the non-weeds. Farmland species depend not only on the seeds and flowers of crops but also on those of the “weeds,” and as the ecosystem loses these overlooked resources, its dependents suffer.

In fact, as Dr. Darren Evans, lecturer at the University of Hull and the study’s lead researcher, has observed, aggressive management of its crops–by cleansing the plot of unwanted plant species–can shrink a farm’s total energy output (in seed and berry biomass) by as much as nineteen percent. In other words, managing the farmland more “efficiently” harms its productivity.

Researchers reached this conclusion by creating and then analyzing “food-webs” that single out those seed-bearing plants most attractive to the ecosystem’s insects and animals. Moreover, as most farms purge their land of weeds in order to better control crop cultivation, with the end of harvest comes a sudden ecological depression: fewer seed- and berry-producing plants have survived to sustain hungry insects and animals through the winter.” Non-farmed habitats, such as woodlands and hedgerows,” Evans continues, “are important for seed resources [...].”

The team’s recommendation to farmers? Benevolence. By permitting some weed species to grow within areas allocated for crops, they can increase both the numbers and kinds of seeds and berries available for animals with an appetite for them. The resulting boom in biodiversity can only bolster the land’s profitability, making the relationship mutually beneficial. So: long live the weed.

Discussion Question: Discuss other methods by which biologists can estimate the amount of loss suffered by farmland stripped of “weeds.”

News Articles:
http://www.sciencedaily.com/releases/2011/09/110929122755.htm,
http://www.seeddaily.com/reports/Weeds_are_vital_to_the_existence_of_farmland_species_999.html,
http://www.upi.com/Science_News/2011/09/29/Study-Farmland-species-depend-on-weeds/UPI-44081317335945/, http://www.menafn.com/qn_news_story.asp?storyid=%7B60d68cf8-7a6c-433b-b8fa-be8656bb70f9%7D

Journal Article: http://www.sciencedirect.com/science/article/pii/S000632071100334X

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

Kava is cultivated in the Pacific, but is consumed across the world. In 2002, Kava was banned from use in various countries because of  improper production of the crop. Nevertheless, Dr. Jerome Sarris from the University of Melbourne, Professor Rolf Teschke from Wolfgang Goethe-University, and Dr. Vincent Lebot from CIRAD believe in the curative possibilities of Kava and have proposed a six-point plan that allows for the plant’s reintroduction. To safely produce Kava, the plan includes using older cultivars of the peeled rhizome, or root, of the plant and to implement a series of quality control measures.

The scientists have published their framework for Kava production in the journals Phytomedicine and The Journal of Clinical Pharmacology. Further, Dr. Sarris is currently conducting human trials on the efficacy of the plant in reducing stress. If the proposed plan for the use of Kava is adopted globally, scientists believe the benefits could be great. However, dosage recommendations and further safety issues must first be investigated.

Discussion Question: Analyze Kava’s composition. Where do you think most of the active ingredients lie?

News article: http://www.sciencedaily.com/releases/2011/02/110228104446.htm
Journal Article (Phytomedicine Journal) : http://www.phytomedicinejournal.com/article/
Journal Article (British Journal of Clinical Pharmacology): http://onlinelibrary.wiley.com/doi/

Scientists at the Institut de Recherche pour le Développement (IRD) are looking at two different species of rice, one African and the other Asian, and researching ways to increase their development and agrarian performance. While the African species is more pathogen resistant and weather tolerant, agronomy shows that the Asian species is the better option. Using genetic techniques, researchers aspire to transfer the valuable properties of the African species to the Asian rice species, hoping for faster cultivation.

Before any genetic modifications can take place, IRD scientists must first overcome the sterility between the African and Asian species. Stemming from the same Asian parent species, part of the rice line became separated in Africa, generating this infertile behavior.  Partnering with the International Center for Tropical Agriculture, IRD researchers determined the genetic markers involved in the sterility. Genome sequencing and mapping reveals the segment of the chromosome that deals with this reproductive hindrance. Identification of the gene gives hope for the future development of a rice lineage that would improve cultivation by producing the Asian species with the precious properties of the African species.

Discussion Question: Can you think of any other methods, besides genetic engineering, that may enhance rice production?

News article: http://www.sciencedaily.com/releases/2011/09/110909111637.htm
Journal article: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0017726