Contributions of Biotechnology to Agriculture

Contributions of Biotechnology to Agriculture Introduction The Food and Agriculture Organization some 20 years ago released a paper stating that the amount of food produced worldwide will not be able to provide the constant nutritional needs for the world population by this year (2010) as a staggering 25% increase in world population was projected, though this estimation has not materialised, it has generated a lot of concerns as there has been a 4-fold population increase in the last century (1918 2009) which has led to the applications of biotechnology to agriculture or in other words the Agrobiotechnology to enhance maximum food production in an economic way. The need for the application of biotechnology to crops was also necessitated as a result of the massive crop loss due to insect pests as at that time was treated with pesticides which are expensive and thus there was a need to sustain the productivity yields of crops which was not given much of a chance as world population was on the rise. Biotechnology was able to provide prospects of producing novel, developed, safer and inexpensive crops in agricultural practices. (Brown, 1992) Agriculture is defined simply as the activities involved in the production of food crops and rearing of livestock animals, while biotechnology was defined jointly by FAO and WHO (1996) as the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services. Therefore Agrobiotechnology techniques according to Huttner et al, (1995) are implemented to reduce cost of production of crops and increasing food productivity by; increasing food quality and food processing traits, adequate disease or pest resistance, improving environmental stress tolerance, and the control of weeds which has led to the development of (genetically modified) GM crops in some parts of the world. Plant breeding techniques with the use of molecular markers such as RFLP, RAPD, AFLP, SSRP, CAPS and SSCP were improved for plants genome mapping as well as to determine plants phenotypes and select desirable traits for the proper modification of crops depending on the gene of interest that is to be incorporated into several populations of plants or crops generated by crosses. (Mohan et al, 1996) Several biotechnology approaches have also been applied in livestock farming basically because there is a general belief that the biotechnological steps to humans are just one step ahead of those applied to animals which involves the modification of animals to observe desirable traits. (Becker and Cowan, 2009) According to Fernandez-Cornejo (2008), the fundamental contributions of the application of biotechnology to agriculture depends on the acknowledgement of its prospective possible benefits and risks, however, this essay will focus on the potential contributions of biotechnology to agriculture (plants and animals) taking into account the advantages as well as the disadvantages of the technology Plant (Crop) Biotechnology Plant biotechnology developments was based on the cell theory as described by Vasil (2007) and has witnessed remarkable expansion in the last 10 years which has focused majorly on making crop production efficient and producing crops with desired traits. Plants and crops need to overcome some Biotic and Abiotic stresses to increase their productivity which led to the introduction of genetically modified (GM) crops about 20 years ago which have been commercialized over the past 10 years either with single traitor multiple traits GM crops as the name implies that genes of a crop are taken and transferred to another crop or already present genes are manipulated with the main purpose of changing the features of the crop in question which may be either the way the crop develops or matures. Addressed in the next paragraph are traits that have been transferred to biotechnology or GM crops to increase their yield. Insect/pest resistance Ferry et al (2005) estimated that 10 20% of major crops are lost to insects or pests and crops are genetically modified to be poisonous and harmful to pests that attack the crops, an example is the application of Bt (Bacillus thuringiensis) genes to grow cotton (in China and South Africa) and corn thereby reducing pesticide use, increasing profits, yields and health benefits to farmers who apply pesticides without protective clothes. (Nuffield Council on Bioethics, 2004) Disease resistance Described in details by Raybould and Gray (1993), fungal, bacterial and viral infestations to crops and plants have been suppressed by genetically modifying plants to be disease resistant for example the ongoing research to reduce the viral and fungal infections to sweet potatoes and bananas respectively. Abiotic stress resistance Motavalli et al (2004) discussed the ongoing extensive research to modify crops to be able to survive in unfavourable environmental conditions such as drought, heat, cold, frost, extreme soil conditions and significantly increase food security for example the use of trehalose genes to grow rice in India to protect it from dehydration. Herbicide tolerance This trait enables a wide range of weeds to be controlled by modifying crops to be resistant to the effects of weed thereby lowering costs of herbicides, reducing tillage and effective weed control measures as discussed in Sharma et al (2002) in the growth of soybeans in Argentina. Improved nutritional value Plant biotechnologies has enabled crops to be modified to contain supplemental nutrients inadequate in diets for example the enhancement of ÃŽ ²-carotene in rice to increase vitamin A to prevent blindness which is as a result of vitamin A deficiency. Biopharmaceuticals Biotechnology applications in plants has been used to produce vaccines and medicines according to Sharma et al (2002) which has enabled production and easy distribution of cheap vaccines as in the modification of potatoes to produce bacterial vaccines for E.coli. GM crops have been widely accepted worldwide (25 countries currently) both in industrial and developing countries as shown in figure 1 mainly because of their advantages which are either economical or environmental. Apart from the fact that plant or crop biotechnology has improved the productivity and yield of crops, other economic benefits in relation to the features of GM crops are further discussed; As described by Nuffield Council on Bioethics (2004), the growth of a large variety of crops by farmers have been enhanced as there a good resistance to biotic (insects, pests or diseases) and abiotic (drought, frost, heat) conditions. With the resistance of GM crops to insects and pests, the use of pesticides is greatly reduced which in turn reduces the costs of growing these crops. Farmers are able to generate more income owing to the reduction of the cost of farming and generation of higher yields which consequently reduce the prices of crops thus alleviating poverty and starvation levels in the economy. GM crops have an improved nutrition levels thus sicknesses and illnesses are consequently averted with a better diet even in underdeveloped countries. Since GM crops can remain fresher over a long period of time for example in tomatoes, the shelf life can be increased in the market. The ability of GMO crops to withstand abiotic conditions such as drought has increased food security while the cheaper production of biopharmaceuticals such as vaccines and other medicines in GM plants has led to a great ease of distribution and manufacture of vaccines thus improving healthcare systems. Environmental benefits of GM crops as discussed by Gatehouse et al (1992); Wieczorek (2003) and Gatehouse (2005), includes the less use or no use of pesticides and insecticides which may be contaminants in the environment (land or water) and could accumulate as residues on foods thus more environmental friendly pesticides can be used while in most cases there is no need to use pesticides. Natural resources sustainability is also improved as there is less use of energy or chemicals (pesticides) while natural habitats are conserved for more efficient applications. GM crops have reduced the pressure on vegetation and biodiversity is maintained while there is a less risk of desertification and soil erosion since GM crops can be grown anywhere irrespective of abiotic conditions. According to the advantages of biotechnology described in figure 2 above, these benefits can only be achieved if the risks and concerns which constitute the disadvantages are investigated, realised and averted. (Mannion, 1995). The potential risks of biotechnology applications to crops and plants can either be health related, environmental or social as further discussed. Wieczorek, (2003) discusses the potential risk of introducing toxins and allergens into GM crops while genetic modification technology is underway is of great concern as there is a potential risk of allergens and toxins being transferred into improved crops while also emphasizing the concerns raised about the use of molecular markers during gene transfer as there is a potential risk of diseases being resistant to clinical antibiotic treatments as a result of transfer of resistance encoding genes which may contain novel bacterial strains. Of great concern as discussed by Hobbs and Plunkett, 1999 is the fact that the long term health effects of the consumption of GM crops over a long time is unknown. Of environmental concerns is the potential risk of GM crops hybridizing with related weeds which may result in superweeds that are more complicated to manage while genetic modification of plants could pose a risk of unintentional gene transfer to non GM crops from GM crops thus the former become wild plants creating ecological instabilities as discussed by Soregaroli and Wesseler, (2003). Wieczorek, (2003) suggests that the release of GM crops into the environment may pose unpredicted and adverse effects as it was emphasized by the fatal actions of Bt corn on the larvae of Monarch butterfly, though the possibility of this happening is very doubtful. Due to the fact that insect pests may get resistant to crop-fortification traits of GM crops, a swift resistance can build up among pest populations as it was feared with Bt crops while biological diversity in nature stand a great risk of being adversely affected as there may be an increase on the reliance of GM crops which could intensif y failure of non-GM crops and put at risk food security. A social concern as discussed by Persley and Siedow, (199) raises the arguments of GM crops being labelled as practiced in the U.S.A where Gm crops carry a label showing a difference in while another concern is the inadequate access to seeds of GM crops or food plants that have been patented as these seeds cannot be saved for replanting. GM crops/food plants have been referred to as unnatural by critics as they are modified by humans and not found in nature as other crops created by God thus causing uproar of religious and ethical concerns as discussed in Knight (2008) while it is feared that these GM plants could someday turn into weeds, adversely affect the natural ecosystem due to direct and indirect impacts on non-targeted plants/crops as described by Azadi and Ho, (2009). Animal Biotechnology Animal biotechnology was described by Cowan and Becker, (2006) as series of techniques by which living beings are genetically modified to benefit humans and animals by exploiting and introducing desirable trait which is as a result of the genetic code being discovered in the early 1950s with technologies including embryo transfer, transgenics, in-vitro fertilization, sexing embryo, cloning and gene knockout but with transgenics being the most commercialized while cloning being the technique surrounded with much controversy. Animal biotechnologies have not received much attention as attributed to plant/crop biotechnology as there is so much controversy surrounding its applications as there is a general concern that these applications could one day be applied to humans since its just a step ahead of the applications to livestock to observe desired traits. Embryo transfer, In-vitro fertilization, sexing embryo and even cloning can be classified as reproducing technologies that have several advantages as described by Gordon, 2004 which includes; the improvement of the reproducing capacities of livestock, the reduction of the level of infertility in animals, enablement of old livestock to donate ovules if they cant maintain pregnancies, the observation of specific sex (male or female) as desired traits while the embryos in all these techniques can also be stored in an embryo bank and can be easily retrieved when required. Gene knockout/targeting techniques has a major advantage of increasing the knowledge of stem cells and similar genes that may be present in humans and livestock and can be use to study diseases and ailments as discussed by Serhan and Ward, (1999). Cloning of animals is also advantageous; as it provides farmers with a range of better performing animals in a generation, is used to improve the population of livestock or endangered animals while inexpensive and many biologically engineered drugs can be modified by using genes that can encode proteins from human as discussed by Van Niekerk, (2005). Application of transgenics which is performed either by microinjection or homologous recombination however is the most advantageous and commercialized animal biotechnology with several examples as shown in table 1, below. As numerous as the advantages and contributions of animal biotechnology are, there are still health, environmental and social concerns that want to constitute as disadvantages to the biotechnology applications for instance the safety of food from GM animals could pose a threat to human health as unpredicted and unintended changes may arise in their composition while environmental issues are based on the break out of gene flow into natural populations as feared especially in superfish as escape into habitats will disrupt natural ecosystems and may cause the introduction of undiscovered genes into the environment. Cowan and Becker (2006). Social acceptance concerns has been a major disadvantage of animal biotechnologies as discussed by Becker and Cowan (2009) which arise from labelling, welfare of animals, genetic biodiversity and trade issues have limited the commercialization of animal biotechnologies. Purpose/ Advantage Animal Models Faster Growth/ Leaner meat Cattle, pig, rabbits, sheep Altered milk composition (higher protein) Cattle Biosteel production in milk Goat Reduced phosphorous in swine feaces (Enviropig) Pig Increased wool production Sheep Disease resistance Pig, sheep, rabbit Xenotransplantation (animal organs for humans) Pig Aquaculture (Growth Hormones of Superfish) Salmon Production of human protein in milk Sheep Production of pharmaceuticals and therapeutics Sheep, cattle Table 1: Applications of Transgenics in Farm Animals. Modified from original source; Cowan and Becker (2006)