Biotechnology’s greatest challenge

THE human race recently passed two milestones that captured brief international press coverage. Late in 1999, the world’s population passed the 6 billion mark, having doubled in only 40 years, and just a few months late, India’s billionth citizen was born. These milestones drew public attention to an issue of international importance: continued population growth and the threat this growth poses for global food security and Earth’s ecosystems.
Presently, 80 per cent of the world’s population resides in developing countries. Despite declining birth rates, the world population will continue to rise, reaching between 8 and 10 billion people by the year 2050. Almost all this increase will occur in the developing countries, where population density is expected to nearly double from approximately 55 people per square kilometre (142 persons per square mile) at present, to 90 to 100 people per square kilometre (260 per square mile) by 2050.
These statistics highlight a reality that may constitute the single most important challenge facing humankind for the coming decades: how can all the world’s citizens be assured access to food supplies, health, and economic well-being, and how can these people be sustained without destruction of the remaining forest and wilderness regions?
The Declaration of Human Rights, Article 25 (1), states “every one has the right to a standard of living adequate for health and well-being for himself and of his family, adequate food, clothing, housing and medical care...” Despite these idealistic words, the Food and Agricultural Organisation (FAO) of the United Nations recently estimated that approximately 800 million people in the developing world do not have access to sufficient food to maintain body weight and perform light activities such as preparing food, caring for family members, or attaining employment. Children suffer most from under-nutrition, which leaves them susceptible to disease and hinders their full physical or mental development.
Surprisingly, that figure is viewed as a partial success. It actually represents a drop in real numbers and a significant reduction since the early 1970s in the percentage of the population in developing countries that suffers malnutrition. Nevertheless, the rate of progress in addressing food insecurity in the developing countries is below that set at the World Food Summit in 1996, which demands that 20 million people per year be removed from the trap of persistent hunger. Regional inconsistencies are also cause for concern. While some regions have seen significant improvements, sub-Saharan Africa is regressing, with the actual number of Africans suffering from insufficient nutritional intake increasing since 1992.
Present and future access to sufficient food depends not just on increasing crop yields –the so-called Malthusian optimism –but is dependent on a complex interaction of factors. The most important of these are the price and availability of agricultural products, access to employment, and the income of purchasing power of any given individual. These in turn are determined by large and small-scale economic factors, international trade policies, and uncontrollable parameters such as weather patterns. Some commentators in the industrialised North currently believe there is enough food in the world and that it just needs to be distributed better. That, in our opinion, is dangerously misleading. It is a delusion to seriously consider that the surpluses of the North can or will be sustained indefinitely to feed present and future population in the south.
Agriculture is the foundation of human nutrition and health and the major economic activity in most developing countries. Reliance on subsidised food imports from the North would undermine the stability and integrity of one of the most important systems of generating wealth in the tropical and subtropical regions. Furthermore, assuming that donations of agricultural commodities can cure hunger in developing countries distracts from the central issue, which is how and where must investment be made to ensure that developing countries can support their own populatons. Even in regions where access to food is not a problem, increasing yields from staple crops frees land, time, and resources for small farmers to invest in cash crops or other income generating activities. While improving crop production in the developing countries will not by itself mean an end to poverty or malnutrition, it will be an essential contributing factor for ensuring the future well being of the vast majority of the world’s population.
It is estimated that keeping pace with growing demand will require a 70 per cent increase in agricultural productivity by the year 2025. The scale and urgency of the situation is compounded by several factors. Increased crop production in the developing counties has traditionally been achieved by bringing more land under cultivation. For example, the area committed to cultivation of the tropical root crop cassava has increased 43 per cent since 1970, while production per hectare has risen by only 20 per cent over the same time. Carving out new cropland from desert or rain forest is not a sustainable or desirable practice and will result in severe depletion of the world’s remaining natural ecosystems.
Indeed, most of the world’s high-quality farmland is already under cultivation, especially in Asia, where land and population pressure is greatest. In some regions the amount of available farmland is actually decreasing as prime agricultural areas are lost to urban sprawl, soil erosion, and desertification. In addition, the tropical and subtropical regions contain approximately 80 per cent of the world’s biodiversity. Loss of this resource to unchecked expansion of agriculture would have disastrous consequences for future crop improvement and pharmaceutical discoveries.
Demographic transitions within the developing countries add another twist to the overall picture. Throughout the developing countries, migration to urban areas is increasing dramatically. In the coming decades, the FAO predicts that rural populations will remain roughly at present levels, and more that 90 per cent of population growth will take place in the burgeoning cities of the developing countries. Thus, significant changes are occurring in the types of demand placed on agricultural systems in the developing countries. The major market for agricultural products will clearly be in the cities. Supplying this growing demand in a consistent manner requires transportation infrastructure, storage facilities, and post harvest technologies that are underdeveloped in many tropical countries.
It is clear, therefore, that significantly increased production from the agricultural systems of the developing countries must be generated and sustained over the coming decades and that this must be attained largely from the land already under cultivation. Achieving these aims on the scales required is a daunting prospect.
Over the last 30 years the practices of the Green Revolution have helped achieve higher crop yields. In this strategy a combination of plant breeding, agrochemical applications and irrigation is used to maximise yields in the cereal crops, especially rice and wheat. By most assessments, this has been a measurable success, leading to a 130 per cent increase in wheat yields in the developing countries since 1970. Over the same period, food prices have fallen on international markets, and the proportion of chronically undernourished people has declined significantly. These agricultural practices have allowed India, the world’s second largest and fastest-growing country, to greatly increase its food self-sufficiency, reduce its financial commitment for food imports, and curb destruction of its natural habitats.
There are also, however, a number of acknowledged negative aspects to the Green Revolution. Reliance on agrochemicals is environmentally damaging, and overuse of irrigation has resulted in loss of soil fertility and consequent reductions in yields in some regions. In addition, the majority of small, resource-poor farmers, who still constitute 75 per cent of the land users in developing countries, can afford to purchase the required chemicals. The major beneficiaries of the Green Revolution have therefore been the larger landowners, whose increased affluence has resulted in even greater divisions between the rich and poor in the developing countries.
Another shortcoming of the Green Revolution was its emphasise primarily on rice and wheat and a failure to address many of the most important food crops of the tropical and subtropical regions. These non-cereal staple food crops have received relatively insignificant research investment over the last 50 years and as a consequence have not attained comparable improvements in yield. Known as orphan crops, these include cassava, the plantain and cooking bananas, sweet potato, taro, sorghum, and millet. Yield increase for these crops lag significantly behind rice, wheat and maize.
For example, for plantain, the fourth most important source of calories in the tropics, yields have improved by a total of only 3 per cent over the last 30 years. Hundreds of millions of small farmers cultivate these orphan crops, relying on them as their primary source of calories and as a source of income when traded in local markets. Billions more will rely on them in the coming decades.
Since the mid –1990s, evidence has accumulated that annual increases in rice and wheat yields are declining, indicating that the strategies of the Green Revolution are nearing their limits and will not by themselves provide the increase in crop production required to supply future demands.
Scientists, agronomists and policymakers have been looking for the next revolution in agriculture. This has optimistically been termed the doubly green revolution, which, it is hoped, will boost crop yields with minimum impact on the environment and benefit the small farmer as well as the larger commercial producer. For many, it is biotechnology –the application of DNA or gene technologies for the agronomic improvement of crop plants- that holds this promise.
Genetic engineering is the best known and possibly the most powerful of these techniques, holding great promise for improving crop yields and the quality and value of agriculture products. Biotechnology allows the DNA, the genetic code imparting a specific trait –for example, resistance to a disease infection or drought – to be identified and isolated from a given organism. Once reduced to a few microliters of sticky fluid, this genetic material can be adjusted as required and introduced into the cells of a given plant to become an integral component of the crop’s genetic make-up. As a result, this new transgenic plant acquires the beneficial trait coded by the introduced genetic material and passes the novel characteristic to its offspring.
The great power of this technology lies in its availability to take genes from any given organism and insert them into crop plants. This capability is rooted in the biological reality that the genetic codes, or genes, for all living organisms are organised in a similar manner and can, with minimal changes, be made to operate in a nonnative genetic background. It is possible, therefore, to transfer genetic information from algae, bacteria, viruses, or animals to plants, or to move genes between sexually incompatible plants species. For example, certain genes isolated from viruses, when inserted into the plant’s genome and expressed by the plant, impart resistance to that virus. Crop plants can be engineered to produce their own pesticides, to have resistance to previously toxic chemicals, to be resistant to disease, or to have higher nutritional qualities.
Technical advances over the last five years have pushed plant genetic engineering into new areas by demonstrating the possibility to simultaneously transfer as many as 12 genes into a plant genome. This greatly enhances the potential to engineer complex disease and pest-resistance pathways to produce more-robust crop plants. Biosynthetic pathways can also be manipulated to produce high value pharmaceuticals and other chemical compounds within the plant tissues. These are then available for direct consumption or for subsequent extraction on commercial scale.
A recent example of this application is the expression of the human growth hormone somatropin in genetically engineered tobacco plants. Production in this manner should reduce the cost of pharmaceuticals, bringing medical treatments within the economic reach of more people in the indusrialised and developing countries. The ability to transfer beneficial agronomic traits across species boundaries, within and outside the plant kingdom, opens a multitude of possibilities limited only by our imagination and by ethical and certain biosafety considerations. If handled in a responsible manner, biotechnology represents a revolution with immense potential impact for the well being of mankind.
The greatest need for improved crop production lies in the developing countries. A major challenge is to ensure that the huge potential of biotechnology benefits those who need it the most: small farmers in the developing countries and the people they feed. Recent advances in scientific research and proven performance of genetically modified crop plants in the field suggest that this new technology could be applied to increase food production in the developing countries. However, harnessing biotechnology to enhance food security and economic development in these countries is problematic. Working with poorly understood tropical and subtropical crop species certainly provides challenges, but the major obstacles to applying biotechnology that fits the needs of developing countries are less biological in nature and more economic and political.
The rapid adoption of the first generation of transgenic crop plants in the industrialised North represents the most successful application of a new technology in the history of agriculture. Transgenic crop plantings have risen from zero in 1995 to 39.9 million hectares, almost 100 million acres, in 1999. In just one year, between 1998 and 1999, the area committed to transgenic crops increased by 44 per cent. Slightly more than 50 per cent of this area consists of soybeans genetically engineered with a bacterial gene that imparts resistance to the herbicide glyphospate. Nineteen per cent is maize engineered to be resistant to European stem borer, an insect that is difficult to control by conventional methods and can cause widespread yield losses in this crop. The remainder is composed of cotton, canola, potato, squash, and papaya containing transgenic genes resistant to herbicides or viral diseases. The present market for transgenic crop is estimated at $2.3 billion per year but is projected to reach $25 billion by 2010.
Currently genetically engineered crops are cultivated mostly in North America, with the United States and Canada harvesting 72 per cent of the planted acreage. Yield improvement have not been dramatic, but these first-generation transgenic crops were designed primarily to improve pest and weed control and to reduce requirements for agrochemical applications. To this end, their success has been dramatic. Monsanto Company claims that 2 million gallons of pesticides applications have been saved in the four seasons since the introduction of corn and cotton expressing a gene from the bacterium Bacillus thuringiensi. When expressed by the plant, this gene produces a protein toxic to insects eating the plant tissues but is completely nontoxic to the human consumer.
In the developing world this first generation of transgenic crops has had less impact, in part because these products were conceived, developed and marketed specifically for release within the economic realities of the industrialised countries, not to address the requirements of developing ones. Nevertheless, enthusiastic adoption of transgenic maize and soybean by farmers in countries such as Argentina, China, Mexico and South Africa show that they can be of relevance in at least some scenarios. Eighteen per cent of all transgenic crops worldwide were planted in developing countries in 1999. Argentina, for example, committed 90 per cent of its soybean crop to genetically transformed plants last year.
The developing countries will continue to benefit from crop biotechnologies developed in the North. For example, India will start cultivating transgenic cotton in the near future. However, as noted above, transgenic crop development has been restricted to a few commercial species grown on a large scale and to date has not been applied to the tropical and sub-tropical food crops that sustain local and regional communities within the developing countries. Using biotechnology to sustain food security requires targeting the specific needs of small farmers in the tropical and sub-tropical regions, where small-scale and subsistence farmers still constitute the majority of the land users.
To have an impact on world health, we must direct resources at producing improved varieties of the important local corn and rice varieties. Genetic engineering technologies must also be developed for the orphan crops such as cassava and plantain on which a large proportion of the population depends.
To date, there has been relatively little improvement in the yield of the orphan crops through conventional breeding, which is often both difficult and time consuming. For example, in Africa, cassava produces on average 7 to 8 tons per hectare, (less than 3 tons per acre) of harvested product. Field trials performed under optimised condition-eliminated pressure from weeds, insects, and virus infections—have demonstrated that yields upwards of 80 tons per hectare (32 tons per acre) are possible. Even under more realistic field conditions, achieving and sustaining production improvements of only a fraction of this will have significant impact on food supplies in many parts of Africa.
Yet progress towards the application of biotechnology to the world’s subsistence crops has been frustratingly slow. DNA technologies and the gene transfer protocols required to find, analyse, and insert transgenes with potential agronomic interest into crop plants were first developed in research laboratories in North America and Europe. The technologies required to initiate research programs and develop new genetically engineered crop plants are relatively expensive and capital intensive. The heavy investments required and high-tech nature of these activities have hindered easy transfer to the developing countries. More importantly, lack of public investment in agriculture research from the late 1980s to the present time has ensured that the majority of research and development has been, and continues to be, directed at crops adapted to temperate climates or at tropical cash crops such as cotton, rubber, coffee, papaya, and pineapple, from which a financial return is expected.
As a result, the majority of biotechnology research and expertise resides within the private sector in the industrialised countries, most especially the United States. By definition, subsistence crops such as cassava, sweet potato, plantain, sorghum and millet have little or no place in these market-driven activities. Commercial enterprises have protected their significant investments through the application of talents and intellectual property rights restricting access of emerging technologies to developing country applications. Either the genes, technological tools, and expertise are not made available for application to tropical crop, or release of the genetically engineered products to farmers in developing countries is blocked or delayed by unresolved property rights issue.
Despite these problems, there are encouraging indications as to what can be achieved when resources are focused on applying biotechnology for the improvement of developing country food crops. system of maize has been transferred into rice, where it is able to boost productivity in the genetically engineered plants by up to 30 per cent.
Agricultural biotechnology is a relatively young discipline, with few resources being dedicated to addressing the problems of the developing world for little over a decade. More time and investment will ensure much greater and far-reaching discoveries. The full genetic sequence of rice and Arabidopsis thaliana –a model plant for genetic research – are now completed and will be published later this year. Coupled with vastly improved systems for analysing how genes control development, metabolism will fuel the development of biotechnology applications for improved crop production.
The successes outlined above represent only a small fraction of the effort required to ensure that biotechnology will fill the needs of the world’s growing populations. ILTAB, for example, is one of only five laboratories actively engaged in developing and applying genetic transformation technologies for the improvement of cassava, a food crop consumed by approximately 600 million people, twice the population of the United States, every day. There are more than 1,700 cultivars of cassava grown in Africa, South America and Asia, and the crop suffers from severe yield reductions due to viral and bacterial diseases and insect pests.
The story is the same for plantain and, indeed, all the other “poor man’s” crops, indicating that the resources presently being committed to the orphan crops are clearly out of scale with the task at hand.
Much grater investments also need to be made in research and development of these food crops. The network of the Consultive Group on International Agricultural Research (CGIAR), which is charged with crop improvement for the developing countries, received an annual budget of around $400 million per year. These resources are thinly spread across a range of socioeconomic and agronomic requirements. Clearly, the resources currently being committed to the new century’s most pressing problem are insufficient. If we are serious about meeting the basic rights of 4.6 billion people in the developing countries, we need to face the challenge more realistically.
Despite the recent negative public reaction to biotechnology, we remain convinced that the genetic engineering of crop plants can play a vital role in addressing the world’s present and future agricultural requirements. The risk of not utilising this new technology to help the developing countries secure their own food supplies and economic development far outweigh the inconclusive evidence of any environmental damage attributable to genetically modified organisms.
As for most complex issue there is no single simple remedy. Biotechnology is not a panacea for world hunger. However, combined with traditional breeding, good agricultural practice, and sound economic policies, biotechnology can improve standards of health and economic security for all the world’s people and close the gap between the rich and poor nations.
We believe that the impetus for successful application of both traditional methods and biotechnology to address crop production must come from the industrialised countries, which possess the vast majority of the world’s financial and technological resources. The mobilisation of these substantial resources to address the needs of the developing world is fundamental to the future well being of the world, its natural resources, and its people. This considerable challenge must be sustained over several decades.
There are no easy answers, no quick fix; instead serious commitments are required from all who can contribute.
Claude M. Fauquet is Cofounder and Director of the international Laboratory for Tropical Agricultural Biotechnology (ILTAB) at the Donald Danforth Plant Science Center, St. Louis, Missouri. Nigel Taylor is a research scientist at ILTAB.