Nanobiotechnology in Agriculture October 2012
In 2011, the global population surpassed 7 billion. A 2009 report, How to Feed the World in 2050, by the Food and Agriculture Organization (FAO) of the United Nations projects that the global population will increase to 9.1 billion by 2050. Analysts find population difficult to predict accurately because of the large number of variables that influence women's fertility rate. However, any such increase in the global population number is likely to place pressure on the world's resources, including food and water. This pressure on resources will likely be compounded by climate change and deforestation, leading to desertification of currently agriculturally productive regions. Land for food crops also faces increasing competition from land for crops for other purposes—such as the production of biofuels and pharmaceuticals. However, companies' recent exploitation of shale-gas reserves is likely to alleviate some of the pressure on land use caused by competition with biofuel crops, particularly if countries such as the United States feel less pressure than they feel today to switch to biofuels.
The FAO predicts that annual cereal production needs to increase by 0.9 billion tonnes and annual meat production by 200 million tonnes by 2050 to respond to the food needs bought about by the growth in global population. The 2050 annual-meat-production figure is 174% of 2009 levels and is so high because the FAO is taking into consideration the increase in meat consumption that often follows an increase in national prosperity and urbanization—a development analysts see in China. Increasing demand for meat puts further pressure on agricultural land because farmers need to grow crops to produce animal feed. Some governments (for example, Saudi Arabia and China) are buying large swathes of land in Africa to fend off future food shortages. Although some companies—for example, Modern Meadow—are developing manufacturing methods to engineer meat, these methods are still a long way from fruition. However, improvements in meat substitutes that are plant, fungus, or microbial in origin may reduce the demand for meat in the next decade.
Policy makers, organizations, and individuals—including nanotechnology specialists—have proposed, and to a lesser extent implemented, many solutions to the impending food crisis. Scientists and companies have applied nanotechnology to try to improve crop growth. One of nanotechnology's advantages is that companies can put molecules into tiny packages and design the packages so that they release the molecule slowly over time in a directed manner. Consequently, farmers can reduce the amount of the molecule—for example, water, fertilizer, or herbicides—necessary to have the desired effect on the crop. Companies are also designing nanosensors, including nanobiosensors, that can monitor aspects of the agricultural environment and plant health. Other nanotechnology uses include nanomagnets to remove soil contaminants, nanomembranes for water treatment in agriculture, and uses in food processing and packaging.
Genetically Modified Crops: The Bubbling Cauldron
In the past 15 years, companies like Monsanto, Syngenta, and BASF have used genetic modification of crops to introduce new, more-favorable traits into crops. Genetic modifications include resistance to specific herbicides and the design of plants to have optimal growth in land that they would otherwise struggle to grow in. In comparison with mammalian cells, plant cells have an extra layer of defense because they have a cell wall creating a unique challenge to scientists trying to deliver DNA fragments (for example, genes) into the cell. However, companies have successfully overcome this challenge by usually either infecting the plant cells with the Agrobacterium tumefasciens genus of bacteria, which they engineer to contain the DNA that they want to put into the cells or by blasting the cells with the DNA of interest using a gene gun. (Scientists fire gold or tungsten microparticles from the gene gun—each microparticle coated with the gene they want to transfer into the cells using the method of biolistics. Scientists have also fired genes into plant cells using nanoparticles and gold nanorods instead of microparticles.)
Although techniques to deliver DNA into plants are now routine, scientists find the delivery of other molecules—such as proteins—into plants more challenging. One advantage of scientists' being able to codeliver proteins with DNA fragments into plants would be to edit the genome of the plant in a specific manner—for example, by targeting the DNA fragment of interest to a certain site in the genome. Researchers led by Kan Wang (director of the Plant Transformation Facility) from Iowa State University have found a way to solve the problem of protein codelivery with DNA. In May 2012, Advanced Functional Materials published Wang's paper online. The paper describes the codelivery of proteins and DNA into onion, tobacco, and maize plant tissues by means of a biolistic method. The scientists used 500-nanometer gold-plated mesoporous silica nanoparticles. They loaded the protein into the pores of the nanoparticles and then coated the nanoparticles with the DNA. The work was partially funded by Pioneer Hi-Bred.
Although nanotechnology can help improve the delivery of molecules to cells to produce genetically modified (GM) crops, GM crops and the foods that derive from them are highly controversial in some parts of the world. A scientific study published online in September 2012 by the journal Food and Chemical Toxicology once again has raised the controversial nature of GM crops. The journal published the findings of scientists—led by Gilles-Eric Séralini—from the University of Caen in France and the University of Verona in Italy. Gilles-Eric Séralini is the president of the Scientific Board of a French anti-GM organization, CRIIGEN. The researchers provided the first long-term study on the toxicity in rats of Monsanto's Roundup-resistant maize (NK603). Roundup is a herbicide from Monsanto that uses glyphosate as its active ingredient. The paper reports that both the GM maize and exposure to Roundup increased rat mortality over the two-year time period in female rats. In the male rats, in contrast, only the GM maize feed, not the Roundup alone, increased mortality. Many scientists have openly criticized the work, particularly Dr. Séralini's statistical analysis. Regardless of scientists' objections to the paper, many GM opposition groups have taken the paper as support for their cause, and some governments are growing more concerned about GM safety.
The recent Séralini-and-coworkers paper has led many people to call for a reevaluation of the European Union's stance toward importing products containing GM crops. The European Union already has a notoriously quite negative stance toward GM crops, granting cultivation rights for only two GM crops: Monsanto's MON810 insecticide-resistant maize and BASF's GM potato Amflora. However, in January 2012, BASF announced its decision to stop selling Amflora and any future GM crops it previously intended to sell in Europe for cultivation because of the hostile environment to GM. Reports in the press indicate that the French National Agency for Health Safety (ANSES), the Russian Institute of Nutrition, and the European Food Safety Agency are all intending to assess Dr. Séralini's study and potentially reevaluate their stances on NK603 maize. The Russian consumer-rights regulator, Rospotrebnadzor, has temporarily banned the import of food and feed containing Monsanto's NK603 maize until the results of the evaluation come in from the Russian Institute of Nutrition. Elsewhere, Bloomberg Businessweek reports that the African Centre for Biosafety has asked the South African government to "ban its [NK603] cultivation, import and export." South Africa currently grows and consumes a large amount of GM maize.
Even in the United States, a country with a reputation for being GM friendly, the media are reporting that this latest study may have changed some people's support for GM. According to a 2011 Congressional Research Service report, 60% to 70% of food products on sale in the United States contain GM crop material. In November 2012, voters in California are going to vote on Proposition 37: "The California Right to Know Genetically Engineered Food Act." If Proposition 37 passes, California will be the first state in the United States to mandate labeling of food products containing GM material. Other states may choose to follow California's lead. However, a more significant impact on food-product manufacturers of GM crop seeds and farmers growing GM crops may be caused by food-product manufacturers' deciding to label food products containing GM across the whole United States rather than just in California to save on labeling costs. This universal labeling decision may make food-product manufacturers choose to source the ingredients for their products from non-GM sources. Also, consumers may actively decide to purchase non-GM-containing food products, reducing the demand for GM crops in the immediate to medium term.
The United States is one of the world's current breadbaskets. However, 2012 has proved to be a difficult year for US crop farmers. Farmers in the United States embraced GM crops in the 1990s because GM crops provided yield gains and reductions in the amount of herbicide and insecticide they required. According to the International Service for the Acquisition of Agri-Biotech Applications' (ISAAA's) Global Status of Commercialized Biotech/GM Crops: 2011 report, the United States grows the most "biotech/GM" crops, totaling 69 million hectares (170.5 million acres) in 2011. The ISAAA says that biotech/GM crop cultivation accounts for "an average adoption rate of 90% across its principal biotech crops." One of the principal GM crops grown in the United States is Monsanto's Roundup-resistant maize. However, problems arise when farmers grow monocultures, because the evolution of Roundup-resistant superweeds can create major problems for farmers. According to a news article by Matt McGrath published by the BBC in September 2012, superweeds are affecting 15 million acres of crops in the United States. This rise in superweeds was coincidental with a disastrous year for food harvesting in the United States because of severe drought conditions. The knock-on effect of drought and superweeds is a leap in grain prices. Although GM crop manufacturers are developing new products that are resistant to several other herbicides—for example Dow Agrosciences' Enlist—some superweed-affected farmers may be reluctant to buy GM crop seeds again in the immediate future. However, ongoing problems with extreme weather conditions (such as drought in the United States and wet weather in the United Kingdom) may encourage other farmers to buy seeds for GM crops that companies have engineered to survive extreme weather conditions.
What do the Séralini-and-coworkers study, Proposition 37, and the development of superweeds mean for companies interested in nanobiotechnology? Although scientists dispute the merit of the Séralini study, it has likely raised the profile of anti-GM rhetoric across a broad area of the world. Proposition 37 and the development of herbicide-resistant superweeds will also likely make GM crops less appealing to food-product manufacturers and farmers in the immediate to medium term. Consequently, potential future uses of nanotechnology products to aid the production of GM crops are likely to be limited in that time frame. However, agriculture is a big business that is becoming increasingly important in a world of diminishing resources and an ever-increasing global population. Consequently, one can envisage that companies creating GM crops will have a new lease on life in the more distant future, and nanotechnology solutions to genetic modification may play an important role at this time.
Improvements in farming efficiencies because of technology implementation in the developing-world economies will help to alleviate food shortages. Farmers are also likely to embrace other, non-GM, crop strategies that improve crop survival in extreme weather conditions. For example, some scientists are attempting to create drought-resistant crops by transferring across to food crops the microbiome of plants that live in drought conditions. In the long term, alternative sources of protein that do not require rearing livestock will alleviate pressure on land resources currently in use to raise crops for animal feed.
Overall, the agriculture business provides many diverse opportunities for nanotechnology to play an important role. But to ensure that public opinion does not turn against products using nanotechnology, companies and scientists will need to prove that these nanotechnologies do not have more of a negative impact on the environment than the problem they are attempting to solve—for example, pollution from excess fertilizer use. Nanotechnologies most likely will play an increasingly important role in agriculture in the next 50 years, providing new and innovative solutions to enable agriculture to meet the food demands of the increasing global population better.