Agricultural-Biotechnology.pdf - Agricultural Biotechnology\"This page is Intentionally Left Blank Agricultural Biotechnology Hemant Rawat Oxford Book

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Unformatted text preview: Agricultural Biotechnology "This page is Intentionally Left Blank" Agricultural Biotechnology Hemant Rawat Oxford Book Company Jaipur India I ISBN: 978-81-89473-23-5 First Published 2008 Oxford Book COlllpany 267, lO-B-Schemc, 0pr 0:arayan ~l\\'as, Gopalpura By Pas, Road,jalpur-3()2018 Phone: 01-t1-2S9rO::', Fax ()1-I-12::")~:;2~ e-mail: oxfordbook(a;Slfy com website: ww",:abdpubhshcr.Lom ©Reserved Typeset by: Shivangi Computers 267, lO-B-Scheme, Opp l\,ara~'an '\1\\",1" Gopalpura By Pass Road, Jalpur 3( >:?.f II H Printed at: Rajdhani Pnn ters, DelhI All Rights are Reserved No part of this publication may be reproduced, !'tored in a retrieval system, or transmitted, in any form or by any means, electromc. mechanical, photocopying, recording, scanning or otherwise, without ~hl' prior written permission of the copyright owner. Responsibility for the filet" stated, opinions expressed, conclusions reached and plagiarism, if any, in thiS volume is entirely that of the Author, according to whom the matter encompassed in this book has been originally created/ edited and resemblance with any such publication may be incidental. The Publisher bears no responsibili ty for them, wha tsoever. , t: I \ r \ I' Preface Agricultural Biotechnology is one of the most important key technologies of the 21 century. It provides great potential in the area of plant breeding. In this way, plants can be developed that provide ingredients for healthier nutrition, grow in unfavourable conditions or form substances that are otherwise produced by means of a complex chemical process. Through biotechnology not only the variety is improved, but yield also improves through growing crops having resistance to diseases, herbicides and pesticides. Through understanding basic concepts of agricultural biotechnology and adopting improved genetically mutated seed varieties, the grower as well as the consumer is benefited a great lot. Agricultural Biotechnology" presents all the latest techniques of plant tissue culture, transformation and bioengineering at the outset and discusses .in detail various issues of plant breeding, cloning, disease resistance, and herbicide and pest resistance. The book makes elaborate presentation on radioimmunoassays, enzyme immuno-absorbent assays, genetic recombination, pharmaceutical products and solar energy that have immensely impacted the field of biotechnology. Hemant Rawat "This page is Intentionally Left Blank" Contents Preface l. Introduction v 1 2. Plants and the New Regimes 33 3. Agro-Food Studies 59 4. Evolving Policies of Biotechnology 85 5. The Alternative Agriculture 111 6. Modern Science of Agriculture 148 7. Green Revolution 180 8. Agriculture Biotechnology in 21st Century 192 9. Importance of Agriculture Biotechnology 203 10. Future of Agriculture Biotechnology 252 Index 274 ,I i I "This page is Intentionally Left Blank" I Introduction BIOTECHNOLOGY AND PLANTS Biotechnology is being used as a tool to give plants new traits that benefit agricultural production, the environment, and human nutrition and health. The purpose of this publication is to provide basic information about plant biotechnology and to give examples of its uses. The goal of plant breeding is to combine desirable traits from different varieties of plants to produce plants of superior quality. This approach to improving crop production has been very successful over the years. propwty 1M ~cn cllrtcl~ Access 10 ~ GenMic R.....c:es For example, it would be beneficial to cross a tomato plant that bears sweeter fruit with one that exhibits increased disease resistance. To do this, it takes many years of crossing and backcrossing generations of plants to obtain the desired trait. Along the way, undesirable traits may be manifested in the plants because there is no way to select for one trait Fig. Plant breeding without affecting others. Another limitation of traditional plant selection is that breeding is restricted to plants that can sexually mate. Advances in scientific discovery and labouratory techniques during the last half of the twentieth century led to the ability to manipulate the deoxyribonucleic acid (DNA) of 2 Introduction organisms, which accelerated the process of plant improvement through the use of biotechnology. MODERN PLANT BIOTECHNOLOGY Plants are made of millions of cells all working together. Every cell of a plant has a complete "instruction manual" or genome (pronounced "JEE-nom") that is inherited from the parents of the plant as a combination of their genomes. Genes are found within the genome and serve as the "words" of the instruction manual. When a cell reads a word, or in scientific terms "expresses a gene," a specific protein is produced. Proteins give an individual cell, and therefore the plant, its form and function. Genes (words) are written using the four-letter alphabet A, C, G, T. The letters are abbreviations for four chemicals called bases, which together make up DNA. DNA is universal in nature, meaning that the four chemical bases of DNA are the same in all living organisms. Consequently, a gene from one organism can function in any other organism. The ability to move genes into plants from other organisms, thereby producing new proteins in the plant, has resulted in Significant achievements in plant biotechnology that were not possible using traditional breeding practices. o _Thymine P I!!I Adenine _Guanine CJ Cytosine O-DeoxyribQs. (sugar) P-Phosphale -Hydrogen Bond Clearly, the ultimate solution to each of these problems is reducing population growth, a difficult challenge that is further complicated Fig. DNA by social, political, economic and religious considerations. In the hope that national and international efforts will help to stabilize world population in the next few decades, our challenge is to use the power of plant biotechnology toward the solution of the numerous problems caused by population growth by increasing productivity, by reducing crop losses, and by protecting and conserving the environment. Introduction 3 Plant biotechnology is not a magic bullet that will solve all of these problems, yet it is becoming abundantly clear that it is the best tool that we have and it can, if used wisely and in a timely fashion, make significant contributions. It is rather ironic that at a time when international agriculture is under increasing pressure to meet the food needs of the ever increasing population, and when plant biotechnology is beginning to make significant contributions to food productivity and environmental safety, it has become the target of well coordinated and sustained attacks by many environmental and self-appointed watchdog groups, particularly in Western Europe and in some of the developing countries. In India, we had faced similar attacks during the 1970' sand 1980' s. However, after extensive public debate, protest demonstrations, court challenges and congressional hearings, a federal regulatory framework was developed that has served the public and the private interest well. It has allowed the plant biotechnology industry to grow and introduce its products into the market place. The Indian consumers and farmers have accepted and benefited from transgenic products. Transgenic crops are being grown this year on nearly 100 million acres of Indian farmland, accounting for 74% of our soybean, 71 % of our cotton and 32% of our com acreages. It is fortunate and encouraging that China and India, the two most populous countries in the world, with increasing demand for food and worsening environmental problems, have recognized the importance of plant biotechnology in agriculture and have established active and successful research and development programmes in plant biotechnology, targeting many regional vegetable and fruit crops, in addition to such staples as wheat, rice, maize, soybean, various pulses, canola, and cotton. It is not too far-fetched to expect that within the next few years these two countries will plant the largest acreages of transgenic crops in the world. Argentina and South Africa are two other developing countries that are increasing their planting of transgenic crops. 4 Introducticm Indeed, at the present time, nearly 10% of the global acreage of transgenic crops is planted in the developing countries. Thus the argument that plant biotechnology is a tool of the industrialized countries for the exploitation of the developing world is no longer sustainable. It is our hope that the success of plant biotechnology in these countries will encourage similar efforts in other parts of the developing world. It is true that the first generation of transgenic crops, which contain genes for resistance to herbicides and insects, did not provide any direct benefits to the consumer. Nevertheless, there are numerous indirect benefits, such as the reduced use of pesticides and herbicides, reduced tillage leading to soil conservation, reduced use of natural resources such as petrochemical products and water for the manufacture, transport and application of agro-chemicals, and reduced labour costs. By producing more food on the same amount of land transgenic crops promote conservation and biodiversity by saving wildlife habitats and precious forests from being converted into farmland. Reduced use of pesticides has already shown a marked decrease in illness and death caused by pesticide poisonings in China and South Africa (nearly 500 cotton farmers in China die each year of acute pesticide poisoning). The vital role of agriculture and food production in human health and nutrition, in poverty alleviation, and in social and political stability, is well known. This was recognized as far back as 1970, when Norman Borlaug was awarded the Nobel Peace Prize for his work that led to the Green Revolution and that helped to save hundreds of millions of lives in the developing countries. Plant biotechnology too can contribute to international peace and security by increasing food production, producing safer and healthier foods, protecting our rather finite natural resources and the environment, and improving human health. It is, therefore, morally and socially irresponsible and indefensible to prevent or delay the applications of plant biotechnology to problems of hunger, health and rotection of the environment. In troduction 5 The opponents of plant biotechnology would have us believe that it is an unnatural and unsafe process that produces harmful products, and that it is totally different from plant breeding and selection that account for almost all of our modern crops. The indisputable fact, however, is that humans have engineered crops for nearly 10,000 years. Almost all of our major crops - such as maize, wheat, potato, tomato and others - are man made. Indeed, none of our modern crops are capable of surviving in the wild without human care. The molecular and genetic principles of plant biotechnology and plant breeding and selection are the same. Plant biotechnology is no different from breeding and selection or for that matter from radiation and chemically induced mutation breeding, except that it is extraordinarily precise and predictable, and is not restricted by taxonomic boundaries. No compelling evidence has ever been presented to show that transgenic crops are innately different the non-transgenic products of breeding and selection. t~ oot ~ssue cunu",~ to :~:'::;ted ::'U~fd:~:entiated 'i " culture with badena I carrying '" mature plant attered T -4 plasmid mature plant ,(herbu:ide-suscePtible ':~~=- ~ embryo ~. :::=~'~i that have grows I n t o " 8 plant and grown In lIQuid QJlture ~ Incorporated • foretgn DNA ~ , redifferentiation of sek:ted cells Into embryos Fig. Transgenic Crops In retrospect, however, we must share some of the blame for the perception that plant biotechnology is different from plant breeding and selection. During the 1970's and 1980's, when there was a great deal of euphoria over the production of somatic hybrids, doubled-haploid breeding lines and transgenic plants, the plant biotechnology community made a serious error in strategy and judgment when it distanced 6 Introduction itself from breeding and selection and established a separate identity for itself. It was us who placed the spotlight on the process and not the product. This has come to haunt us now as it has attracted undue and undeserved attention and opposition. It was also an error not to engage early in the debate on transgenic plants, . and to permit the opponents of plant biotechnology to dictate the agenda. As responsible members of the world community, and as scientists, we cannot, and should not, be silent observers of this debate. We must play an active role in the debate on plant biotechnology and make an informed and professional contribution to the public dialogue, emphasizing the many benefits of transgenic crops to human health and the environment. The opposition to transgenic foods in Europe and elsewhere is based exclusively on political and ideological differences rather than on any credible scientific evidence. On two rare occasions an attempt was made to present scientific arguments against the use of transgenic crops. These involved the allegedly harmful effect of pollen from Bt maize plants on the larvae of the Monarch butterfly, and the alleged transgene contamination of maize in Mexico. More detailed investigations by several research groups have since refuted these claims and showed them to be of dubious scientific value. Indeed, in the Mexican maize story, the journal Nature, in an unprecedented action in its more than 100 year history, was forced to disown the paper published in its own pages. The consumer, tl}e farmer and the biotechnology industry have been ill served by the sustained campaign of misinformation and unsubstantiated claims of dangers to public health and the environment by transgenic crops and their products. After more than ten years and thousands of field trials in many countries, after nearly a decade of commercial plantings on hundreds of millions of acres, and after transgenic food products having being used by hundreds Introduction 7 of millions of humans and farm animals, there is not a single documented instance of illness reported in any human or animal, or of ecological or environmental damage. What then is the basis and rationale for the many restrictions still placed on the field planting and human use of transgenic foods? The enviable and unblemished record of transgenic crops and their products is the strongest evidence for their safety and wholesomeness. The opponents of plant biotechnology should compare this record with that of the many drugs approved for human use in the United States. In an exhaustive study published recently in the Journal of the Indian Medical Association, it was reported that 20% of the 548 drugs approved for human use during the past 25 years were later found to have serious or life-threatening side effects. Seven of the drugs possibly contributed to 1002 deaths, and 16 were forced to be withdrawn from the market. In comparison, not a single transgenic food product has ever been shown to have any harmful effects, and none has been withdrawn because of adverse reactions in humans or animals. The plant biotechnology community has already done more for the environment and the developing countries than the self-proclaimed environmental groups and the so-called friends of the poor. Indeed, the opponents of plant biotechItology have done much harm to their professed cause by slowing down and/or preventing the planting and utilization of transgenic crops around the world. The contributions of the plant biotechnology community, on the other hand, are socially and morally responsible and of considerable humanitarian value. We have every reason to be proud of these contributions. The rules and regulations adopted for transgenic crops in the 1980's were both prudent and necessary. At that time there were many unknowns about transgenic crops and about their possible effect on humans and the environment. There was a need to establish a database to satisfy the concerns of the general public as well as the scientific community. Three federal agencies, the United States Department of Agriculture, 8 Introduction the Environmental Protection Agency and the Food and Drug Administration, were given oversight responsibilities for transgenic crops. The resulting open and transparent system established in the United States has worked well and has served its purpose. It has done much to gain the confidence and support of the American public for plant biotechnology and its products. In light of the demonstrated safety of transgenic crops to humans, animals and the environment, the question must be asked whether it is any more necessary, or even advisable, to continue the expensive, time consuming and burdensome requirements for the public release of transgenic crops and their products (field trials of transgenic crops are 10-20 times more expensive than of similar plants developed by conventional means). I propose that based on our considerable experience and on the vast amount of information gathered about the safety of transgenic crops over the past decade, it is time for our regulatory agencies to consider whether some or all of the current regulatory requirements can be gradually relaxed and ultimately suspended, except in those rare instances where there is the clear likelihood of risk to human health and the environment. Genuine concerns about gene flow and development of resistance to antibiotics, and pests or pathogens, can be met adequately with currently available and emerging technologies. The process of deregulation of transgenic crops, controversial and difficult as it may be, needs to begin now because the continuation of the present rules and regulations is entirely unnecessary, unjustified and counterproductive. In order to be effective and acceptable, the process should be open to all points of view. The decisions, however, must be based on science and facts and not on political or ideological considerations. Nearly two decades ago, the United States played a leading and useful role in establishing the rules and regulations for the field planting, evaluation and human use of transgenic crops. It should now playa similar role in having these restrictions relaxed and removed. Introduction 9 It is clear that the challenges we face in the 21st century are greater than those we faced in the last century. Of all the available technologies, plant biotechnology offers the best hope for producing more and better food, fiber and pharmaceuticals, and for protecting, preserving and improving the environment for the benefit of humankind. My owrrronfidence in plant biotechnology comes from knowing that the science behind it is sound, that it is well tested and proven, that it benefits the consumer, the farmer and the industry, and that it protects and conserves the environment. It is for these reasons that I am convinced that plant biotechnology will within the next two decades become an integral part of the international agricultural system. With the United States, China, and lately India, three of the most populous countries in the world serving as examples, we have taken the first steps toward achieving that objective. Introducing Genes into Plants To genetically modify a plant, the thousands of bases of DNA comprising an individual gen..: are transferred into an individual plant cell where the new gene becomes a permanent part of the cell's genome. This process makes the resulting plant "transgenic." Transfer of DNA into plant cells is done using various "transformation" techniques that are the result of discoveries in basic science. One method to transfer DNA into plants takes advantage of a system found in nature. The bacterium that causes" crown gall tumors" injects its DNA into a plan~ genome, forcing the plant to create a suitable en...
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