Stanford Scientists Identify Key Trigger for Nitrogen Fixation in Legumes

There is widespread agreement that nitrogen-fixing legumes must play an increasingly central role in tomorrow’s sustainable farming systems, as the price rises and availability wanes of fossil-fuel-based nitrogen (N) fertilizers. One of the Holy Grails of plant biotechnology has been finding and moving the genes responsible for nitrogen fixation into corn and grains like wheat and rice, crops that are now largely dependent on N fertilizers on conventional farms.

A team of scientists at Stanford University led by Dr. Sharon Long has found a key protein that must be present to trigger nitrogen fixation by bacteria colonizing the roots of legumes. This important discovery was made possible by the tools of agricultural biotechnology. How this breakthrough finding is exploited by plant breeders will be closely watched and no doubt controversial.

Dr. Long explained one promising application in a press release from Stanford, “Plant breeders who are trying to help develop better-adapted plants can now analyze traits such as this. We’ve given them a new tool.”

Marker-assisted breeding with a wide variety of legumes will likely be explored, but so too will the creation of transgenic plants engineered to have the capacity to produce or up regulate (i.e., produce more of) the key N-fixation protein.

Sources: Wang, D. et al., “A Nodule-Specific Protein Secretory Pathway Required for Nitrogen-Fixing Symbiosis,” Science, Vol. 327, page 1126-1129. February 26, 2010.

“Legumes could help reduce nitrogen spread,” Stanford University Press Release, via ScienceDaily.com. No date.

More Evidence of How OP Insecticide Exposures Trigger the Metabolic Syndrome

Another major paper has come out in Environmental Health Perspectives linking organophosphate (OP) insecticide exposures during fetal development to predisposition to metabolic syndrome. The new paper identifies a key mechanism leading to adverse developmental outcomes – alteration of the trajectory of cell signaling in liver cells “…in a manner consistent with the observed emergence of pre-diabetes-like metabolic dysfunction.”

Source: Adigun, A.A., et al., “Neonatal Organophosphate Pesticide Exposure Alters the Developmental Trajectory of Cell-Signaling Cascades Controlling Metabolism: Differential Effects of Diazinon and Parathion,” Environmental Health Perspectives, Vol. 118, No. 2, pages 210-215, February 2010.

Nicotinyl Seed Treatment Exposures Through Guttation Droplets

As a normal part of respiration, plants emit what is called guttation droplets – one source of the morning dew that can be seen on plant leaves even on dry spring and summer mornings. Guttation droplets are a favorite source of drinking water for bees right after they leave the hive in the morning. Guttation droplets provide bees with moisture, some nutrients, and now in many areas, a daily dose of pesticides.

German scientists have found residues of the major nicotinyl seed treatments imidacloprid (Gaucho) and clothianidin (Poncho) in guttation droplets on corn, canola, and barley plants. The levels are typically highest in the first 10 days after plant germination and were as high as 100 milligrams per liter (parts per million [ppm]). Two weeks later the levels had fallen to 10 mg/l (ppm). Levels over 1 ppm persisted for as long as two months.

Imidacloprid levels in corn and canola plant pollen average around 3.4 microgram per kilogram of pollen, or ug/kg [parts per billion], in fields planted to seeds treated with commercial rates of Gaucho. This is about 1,000-times lower than the nicotinyl levels measured in Guttation droplets.

Imidacloprid (Gaucho) is known to induce sublethal effects on honeybees after exposures as low as 0.1 nanogram per bee – a nanogram is one-billionth of a gram, a very, very small amount. Many studies have documented a range of significant impacts in the 1 ng/bee to 20 ng/bee range.

A honeybee would have to consume a very tiny fraction of one drop of water containing 100 ppm of Gaucho in order to consume 1 nanogram of Gaucho. This is why the new findings about seed treatment insecticides in guttation droplets demand strong and rapid action – if protecting bees is indeed a priority.

Source: Schenke, D. et al., “Pesticides in guttation droplets following seed treatment – Preliminary results from greenhouse experiments,” Abstract from the Institute for Ecological Chemistry, Berlin, Germany. 2010.

“Pesticide Stew” in Beehives and Pollen Triggers National Attention

At a March 25, 2010 session during the annual meeting of the American Chemical Society, a team of USDA-funded scientists reported finding a veritable “stew” of pesticides in bee hives, pollen, and beeswax.

Three out of five pollen and wax samples from 23 states included at least one residue of a systemic pesticide.

121 different pesticides were found in 887 samples.

The average sample of beeswax contained 8 pesticides and/or pesticide metabolites and one sample contained 39 – how’s that for a pesticide stew with a long ingredient list?

The finding of so many pesticides in beeswax is no surprise given what the bees were carrying back into the hive. The scientists also measured pesticides in the pollen collected by bees for transport back to the hive.

Seven pesticides were found, on average, in each of 350 pollen samples, and one had 31 pesticide contaminants.

Out of 887 samples of beeswax, pollen, and bees themselves, only 16 (1.8%) had no detectable pesticide residues.

Sources: Burke, S. and S. Borenstein, “Plight of bees worsens this winter and scientists spot stew of pesticides in pollen, hives,” Associated Press, March 24, 2010.

Janet Raloff, “Bees face ‘unprecedented’ pesticide exposures at home and afield,” Science News, March 21, 2010.

Omega-3 Intakes and Heart Health – More Good News

For every 5% increase in polyunsaturated fat/omega-3 intake, the risk of coronary heart disease goes down 10%, according to a just-published meta-analysis by Harvard Medical School scientists.

Consuming foods containing omega-3 fatty acids has now been shown to improve blood vessel health following a meal, combating stiffness in blood vessels that contributes to cardiovascular disease.

Sources: Stephen Daniells, “Replace saturated fats with omega-3 to boost heart health: Harvard Study,” www.foodnavigator.com, March 24, 2010.

Stephen Daniells, “Omega-3-rich meals have blood vessel benefits: Study,” www.foodnavigator.com, March 16, 2010.

Glyphosate + Parasites = Fish Kills and Malformations

New Zealand scientists have discovered synergistic effects between exposure to environmentally-relevant levels of glyphosate herbicide and parasites of aquatic vertebrates including snails and fish. Parasites alone or glyphosate alone did not trigger spinal malformations in fish, but the two together did.

The findings suggest that regulatory authorities need to take into account the multiple contaminants and stressors in aquatic environments when carrying out risk assessments.

Source: Kelly, D.W. et al., “Synergistic effects of glyphosate formulation and parasite infection on fish malformations and survival,” Journal of Applied Ecology, Vol. 47, page 498-504, January, 2010.

Weighing Organic Costs and Benefits

A March 23, 2010 story in the Chicago Tribune by Julie Deardorff summarizes the benefits of organic fruits and vegetables, dairy and meat, cosmetics and personal care products, processed foods, and cotton and coffee. The piece draws heavily on Organic Center reports and findings.

The section on pesticides highlights the neurological development risks to the developing fetus and infants and children. Discussion of organic meat and milk focuses on the positive impacts of pasture on omega-3 levels (up) and saturated fat (down) levels. TOC Chief Scientist Chuck Benbrook is quoted as saying –

“Pushing animals to grow really fast has a cascade of effects on the environment and the health of the animal. We need to back off the accelerator and focus on the health of the plant, the health of the animal, as well as the nutrient composition of food.”

The syndicated story has run in hundreds of papers, including in the L.A. Times on March 29. Access the 40+ comments by readers on ”Julie’s Health Club” blog.

Source: Julie Deardorff, “Is organically grown food safer or more nutritious? Consumers should weigh the cost vs. benefits,” Chicago Tribune, March 23, 2010, pages 1 and 4.

Childhood Obesity “Worse than Thought”

A chilling study of 700,000 children and teens in southern California reports that more than 6%, or 45,000, were “extremely obese,” almost twice the share found in an earlier study. A child is “extremely obese” if they weigh 1.2 times more than the child at the 95th percentile for their age and sex. According to Dr. Amy Porter, a scientist working for Kaiser Permanente and a study co-author –

“Without major lifestyle changes, these kids face a 10 to 20 years shorter life span and will develop health problems in their 20s that we typically see in 40-to-60-year-olds.”

Source: JoAnne Allen, “US child obesity problem worse than thought,” Reuters Health Information, March 19, 2010.

Attacking Childhood Obesity at the School Lunch Counter

Both the White House and Congress are pushing hard to provide new funding and direction for the school lunch program. A New York Times editorial on March 25 traced the growing national resolve to dramatically improve the quality of food served children in school to Michelle Obama’s White House garden. The First Lady recently called upon the food company members of the Grocery Manufacturers Association to step it up –

“We need you not just to tweak around the edges, but to entirely rethink the products that you’re offering…”

Senator Blanche Lincoln (D-Ark) is moving a bill through the Senate Agriculture Committee with a $4.5 billion funding increase for the school lunch program, coupled with several other policy changes designed to increase consumption of fruits and vegetables, and locally grown and organic food.

A March 15 op-ed by Chris Koger in the “The Packer” covered much of the same ground, triggering this “Letter to the Editor” from Chuck Benbrook that ran in the March 29 edition –

Dear Editor:
I agree with Chris Koger’s upbeat assessment of prospects for expanding sales of fresh fruits and vegetables, as described in “Uncle Sam gives a chance to sell more produce” (March 15, 2010). Taking full advantage of this window of opportunity, though will require systemic effort across all levels of government, the food industry, and steady pressure from moms and dads (and grandparents).

Three steps are key. The produce and food industries must deliver a much more diverse, high-quality and tasty suite of product options, and year round, from snacks to side dishes to desserts (not too sweet) and beverages. Second, in the next farm bill cycle, Congress needs to shift a significant share – like 25% - of farm program subsidies from corn, soybeans, and indirectly saturated fats in animal products, to healthier fresh, frozen, and canned fruit and vegetable products. Third, unhealthy food that is driving health care costs upward should be taxed more heavily and for the same reason that cigarettes are taxed, an approach that research shows will work to shift consumption patterns. Patience and perseverance will also be needed since human behavior, and especially dietary patterns, are hard to change.

Gruesome Story Highlights Impacts of Endosulfan

On March 18, 2010, the “60 Minutes” newsmagazine in Australia broadcast a segment entitled “Poisoned.” It covers the risks associated with pesticides applied in a macademia nut grove in Queensland, with special focus on the endocrine disruptors endosulfan (Thiodan) and carbendazim. According to the report, 62 countries have banned the use of endosulfan – Australia and the U.S. are among those that have not.

Endosulfan and its metabolites are among the most common pesticide residues found in vegetables tested by the USDA’s “Pesticide Data Program.” In 2007, endosulfan residues found by PDP posed significant risks in kale, squash, broccoli, green beans, celery, tomatoes, and collard greens – seven of the nine vegetables tested that year.

The segment covers fish embryos born with two heads and without eyes following exposure to the pesticides applied on the nut farm. A 24-year-old man in the U.K. blames his mother’s fungicide exposures for his disabilities – he was born without eyes. His mother had sprayed a fungicide similar to carbendazim in their garden.

In the State of Kerala in India, endosulfan is widely used on cashew plantations and came to contaminate local water supplies, triggering an epidemic of birth defects and health problems.

The transcript of this broadcast provides further details on this chilling story.

Seven Predictions for 2010

In a March 15, 2010 press release, the Center offered seven predictions for 2010 and beyond, unless the country starts to systematically address the core provides in how food is grown and processed in America.

1. An increase in the number of children facing developmental issues including autism, ADHD, birth defects and allergies.
2. An increase in the number of Americans who are obese, diabetic, or both.
3. A decrease in the efficacy of life-saving antibiotics.
4. An increase in disease linked to inflammation.
5. An increase in the spread of ‘super weeds.’
6. The continued decline of the honey bees.
7. More global warming in the absence of changes in farm and conservation programs.

The release concludes with a quote from Chief Scientist Chuck Benbrook –

“The American food system faces profound challenges that will grow worse if the nation fails to astutely and honestly identify the core problems eroding our health and the health of American agriculture. We need new technologies and systems that prevent problems and sustain high levels of soil productivity. Organic farming is a good example of just such an advanced, systems-based technology.”

Bt Corn Efficacy Problems Cloud 2009 Performance

University of Minnesota entomologist Ken Ostlie reports that corn rootworms did serious damage in many fields in several states planted to triple-stack corn genetically engineered to control the corn rootworm. There is no clear explanation for the control failures, although resistance triggered by a lack of adherence to refuge requirements (i.e., planting some non-Bt corn in a field planted to Bt corn) is a distinct possibility, according to Ostlie.

A Missouri study found a 12-fold increase in corn rootworm beetle survival after just six generations of insects were exposed to Bt corn for rootworm control.

Recent surveys by the National Corn Growers Association suggest that about one-third of growers are not adhering to the refuge requirements. Ostlie worries that this degree of non-compliance may be all that is needed to trigger resistance in localized corn rootworm populations, and once resistance genes exist, they will spread and it won’t matter any longer whether farmers adhere to refuge requirements.

Source: Greg Horstmeier, “Rootworms Strike Back,” Progressive Farmer, March 11, 2010.

Interesting factoids about food, farming and the environment

In This Issue:

• Breaking Science
• In The News
• Do You Know?
• Events and Presentations
• Core Truths
• The Art of Giving
• About THE SCOOP
• About The Organic Center