The combination of rice and beans is the trademark of Brazilian cuisine, with the "carioca" type of brown beans accounting for 70% of the consumption of these legumes in the country. It is a typical Brazilian staple: there is no import of carioca beans – only black beans are imported. Hence, if we want to continue enjoying carioca beans in our daily meals, we have to guarantee the national production.
Brazilian consumers may have noticed that the price of carioca beans has increased significantly, reaching up to 16 BRL per kilo in some regions. The reason behind this rise is a plague caused by the Bean Golden Mosaic Virus.
Whiteflies transmit this virus, and an infected crop can suffer a yield loss of 40% -100%. Whitefly infestation affects crops mainly in the warm central regions of Brazil (states of Mato Grosso, Goiás, Bahia, Pernambuco, Minas Gerais, São Paulo, and Paraná, as well as the Federal District). Only the southern state of Rio Grande do Sul is free from the plague, thanks to its colder temperatures – a scenario that can change rapidly in times of global warming.
Notably, plants infected by the virus do not grow. Instead, they become yellow, and their leaves assume the appearance of a green and yellow "mosaic". Ultimately, pods and grains are not viable. Plants can hold up to 300 insects. On their side, whiteflies proliferate quickly. Their life cycle lasts only 19 days, from egg to adult. The nymphs – insects that have just come out of the eggs – can also transmit the virus, sucking the sap out of the plant. When flies get the virus from a contaminated plant, they spend the rest of their lives with the ability to transmit it to other plants. Beans are especially susceptible to them.
The decrease in yield of carioca beans leads to the rise in imports of black bean.
Fear of technology
Using national technology, Embrapa (Brazilian Agricultural Research Corporation) has developed a genetically modified bean resistant to the virus (RMD beans). After a long journey since its development in 2004, and its approval by CTNBio (Brazilian National Biotechnology Regulatory Comitee) in 2011, RMD beans were released for commercialization at the end of March this year. Nevertheless, the decision is under threat.
The Sectorial Chamber of Beans has called for a meeting to discuss RMD beans, motivated by a joint note from Ibrafe (Brazilian Bean Institute, Pulses, and Special Harvests) and CBFP (Brazilian Council of Beans and Pulses). The associations expressed "the need for the GMO seeds to be incinerated so that we eliminate the risk that this cultivar could somehow be used in the future."
In fact, the alleged motives suggest a deep ignorance of the technology employed and an excessive fear of public reaction. They include a supposed lack of evidence on the food safety of Genetically Modified Organisms (GMOs) and the lobbying against GMOs carried out by NGOs and anti-GMO associations. As for the first point, there is already a scientific consensus that genetically modified foods are as safe for human consumption as their conventional counterparts.
The problem
Information from Embrapa Arroz e Feijão (Rice and Beans) estimates that the loss of production caused by the surge of whiteflies would account for between 90,000 and 300,000 tons of carioca beans. This amount is enough to feed between 6 and 15 million people. In the absence of virus-resistant beans, the only way to combat the golden mosaic is by eliminating whiteflies with insecticides.
The cost of the indicated insecticides – plural here – is high. A single insecticide or a single application is not enough. To protect their crops, farmers need to use a cocktail of poisons (a combination of three or four molecules) and over 15 to 20 application cycles. The treatment price is around 80 BRL to 150 BRL per hectare, per application. The toxicity of the products used is also high.
Moreover, the environmental impact of overuse of insecticides – for example, on bee mortality – is a cause for concern. In addition to financial cost and environmental damage, the remedy is not fully effective. The prolonged and excessive use of insecticides ends up selecting populations of resistant whiteflies, able to survive the diverse applications.
Certainly, this scenario creates a risk that producers are often unwilling to take. Thus, we have two outcomes: either the producer pays the price of pesticides and guarantees yield, or gives up beans in the first crop (earlier in the year, in the warmer months), and replaces it with other crops. Both decisions result in significant increases in price for the final consumer, either to cover production costs or the lower supply. Moreover, if producers lose part of the yield, even using the various applications of the insecticide cocktail, this loss will also be computed in the final price.
The solution
Nevertheless, there is a virus-resistant bean, exempt from whiteflies and insecticides, created by Brazilian scientists.
The Embrapa team, led by Francisco Aragão and Josias Faria, used a strategy called RNA interference (RNAi). It is basically about imitating a gene silencing mechanism that already exists naturally. In nature, when the virus infects a bean, the plant develops what we call small interfering RNAs (siRNA), which are nothing more than an immune response of the plant to the infection.
Unfortunately, the natural process takes time to occur, and the plant eventually develops severe symptoms of the disease. The same occurs with humans in several infectious diseases: the immune system responds, but sometimes the disease is very aggressive, and the patient dies. For many serious infectious diseases in humans, we have vaccines. Aragão and his team used a very similar technique: a vaccine for beans!
The mosaic-resistant bean produces these small RNAs – which prevent the virus from replicating in the plant – faster and more efficiently than the natural response. The method not only saves the plant but also controls the spread of the virus, prevents the disease from circulating, contaminating more flies and, consequently, more crops. In humans, we call this "herd immunity"; when a large part of the population is vaccinated, the disease can no longer circulate.
Significantly, this is considered the most effective measure in disease control. As with all GMOs, the beans were subjected to all the tests required by Brazilian legislation and approved by CTNBio in 2011.
Several countries have adopted the same Brazilian technique to grow plants resistant to other types of virus, such as maize (South Africa), tomato (Cuba), and cassava (USA). Our beans were also chosen as a biosecurity model in the international project "GMO Environmental Risk Assessment Methodologies (GMO-ERA)" for the application of a new public policy analysis methodology called Problem Formulation and Options Assessment (PFOA).
Debate
The PFOA proposal is an analysis methodology that takes into account the participation of government, scientists, and citizens. Embrapa's bean was selected as a model in the debate because it was still in the testing phase at the time, represented an essential staple to the Brazilian culture, and involved both small and large producers.
The study group was attended by representatives of supermarkets, housewives' associations, consumers, environmentalists, agricultural cooperatives, producers, and researchers in rural sociology. The group issued a favorable opinion to RMD beans, noting the advantages for producers and final consumers, the reduction of the use of agrochemicals, and the need for transparency for consumers, respecting their right of choice.
That is, the beans were evaluated by a diverse and representative set of different stakeholders of the Brazilian population, and it was approved. Even associations notoriously opposed to the use of genetically modified foods, represented in the study group, agreed with the approval of RMD beans.
Fewer pesticides
A survey conducted by the Brazilian Association of Cereal Companies showed that 76% of bean farmers face the golden mosaic issue, and only 38% of them manage to control the pest. Eighty-six percent see the possibility of having a resistant GM bean as positive and declare that they intend to acquire the seed when it is available in the market. Among the comments in the responses, we highlight "costs are high, sometimes makes planting unfeasible; [we have] to be able to make planting feasible from January to March; we will have a healthier, pesticide-free bean for consumers."
The packaging industry is more divided: 50% of its players say they would buy these sturdy beans. However, it should be noted that the justifications of the 50% who are worried about the commercialization of the beans are based on the fear of the labeling, and the reaction of the final consumer, motivated by the strong anti-GMO movement of Brazil. Players of the packaging industry argue that the consumer still has doubts about the safety of genetically modified foods, and they fear the pressure of negative lobbying by NGOs.
Notably, the issue of safety is a false controversy: there is no reason to assume, in principle, that genetically modified foods are less safe than those developed by techniques considered "natural" for breeding, and each GMO undergoes tests and studies that represent a level of demand that does not exist in other branches of agriculture. Embrapa's beans fulfilled all these steps.
In his book on the interface between science and society on the issue of GMOs, entitled "GMOs Decoded", social scientist Sheldon Krimsky points out as the main causes of resistance to GMOs the perception that there would be excessive uncertainties and risks arising from the transfer of genes between organisms that are very distant from one another on the tree of life (vegetables and animals, for example) and economic issues – the bundling of agrochemicals and seeds, the support for monoculture and "neoliberal models" of agricultural production, etc.
Leaving aside for a moment the merit of these objections – the perception of risk, for example, is false –, the fact is that the beans resistant to the golden mosaic produced by Embrapa do not fit in any of them. The RNAi expressed by the modified plant is the same that already exists in the common plant infected by the virus. That is, there is no "alien" molecule created by genetic alteration.
Also, the variety was not developed by "evil" global companies, not coupled with the sale of pesticides – quite the contrary – and, finally, carioca beans are certainly not a staple targeted by the global monopolist agribusiness. Therefore, there is no excuse to keep RMD beans out of the national market.
Natalia Pasternak is a researcher at the Institute of Biomedical Sciences (ICB) at USP, national coordinator of the Pint of Science scientific outreach festival for Brazil, and president of the Institute Question of Science