GM CROPS AN UNDERSTANDING OPTION AND SUGGESTION FOR CREATING PUBLIC AWARENESS by Prof.S.C.Mishra Dean, Extension Education UAT, Bhubaneswar

Transcription

1 GM CROPS AN UNDERSTANDING OPTION AND SUGGESTION FOR CREATING PUBLIC AWARENESS by Prof.S.C.Mishra Dean, Extension Education UAT, Bhubaneswar

2 1. A growing population, Global warning and loss of bio-diversity have a tremendous impact on our environment 2. Global feed demand is going to be three folds by the year 2050 when the world population is expected to reach 10 billions 3. Feeding these people will mean massive charges in the production, distribution and stability food products 4. For sustainable agricultural production and to meet the future needs agricultural research will have to use rapidly developing modern bio-technology 5. Potential benefits which can be accrued from agricultural biotechnology include higher yield, better quality and creation of novel crop with more adaptive value

3 6. Modern biotechnological techniques have enabled the introduction and expression of novel genes from different sources in to the hast plant. 7. As a result, plants can now be engineered to produce significantly higher yield, better quality as well as resistance against insects, pests and tolerance to herbicides. 8. Transfer of a specific gene from any source by passing the kingdom barrier, species barrier or from synthetic DNA to a hast plant/animal/ organism etc. through technique other than sexual/ parasecxual reproduction refers to Genetic Engineering.

4 9. The objective of such gene transfer may be to obtain (i) (ii) (iii) Multiple copies of the gene/dna segment called gene cloning Large quantities of the proteins produced by the cloned gene or Integration of the gene into the genome of the host organism called gene transfer 10. Genetic engineering is invariably based on recombinant DNA molecules called as Recombinant DNA technique. 11. A recombinant DNA molecule is constructed by joining together two or more different DNA segment/ molecules. More specifically recombinant DNA is the vector into which the desired DNA segment has been integrated.

5 The term Biotechnology was coined by Hurgarian agricultural engineer named Karl Erky,, early in the 20 th century meaning all such work by which products are produced from raw materials with the aid of living oganism.. To day bio-technology is viewed as a group of useful enabling technologies with wide and diverse application in agriculture, health care, animal/livestock, industry and environment.

6 Recent development in the DNA technology has made it possible to mobilize genes of interest within and across the plant and animal kingdom. It is now possible to identify, isolate, transfer and express genes almost at will and thus develop transgenics or genetically modified (GM) plants with novel traits.

7 21 st century is era of biotechnology diverse application like gene-theraphy theraphy,, genetically modified foods and crops food processing technology, biochips, biosensores,, synthetic seeds, production of secondary metabolites, biopesticides transgenic animals/plants, enhances of self life of biological products of biomass energy will revolutionize the traditional agriculture and environmental management.

8 Hence Genetic Engineering for transgene in plant for i. Modifying yield potential ii. Insect resistance iii. Disease resistance iv. Herbicide resistance v. Abiotic stress tolerance vi. Improved nutritional quality vii. Post harvest loss.

9 Bio-technological tools have hastened the following agricultural activities i. Wide hybridization ii. Micro-propagation through tissue culture iii. Cytoplasmic diversification iv. Tagging allin genes with molecular markets v. Somaclonal variation vi. Development of molecular maps vii. Marker aided selection viii. QTL mapping ix. Pyramidiring major genes x. Chromosomal mapping and identification of gene

10 Genetically modified food The food prepared from the produce of genetically modified crops GM food differs from the produce of the conventionally developed varieties. GM Food 1. Contain protein produced by the trans-gene e.g. cry protein in insect resistant variety 2. Contain enzyme produced by the antibiotic resistance gene 3. Contain antibiotic resistance gene could lead to the flowing problem when they are consumed (i) (ii) (iii) (iv) may cause toxicity may cause allergies enzyme produced by the antibiotic-gene could come allergies antibiotic resistance gene through GM food caused by the animals/human being may develop assistance to the antibiotic

11 The estimated global area of GM crop during 2003 was 67.6 million hect.. Covering 21 countries 7 million farmers and 6 crops amounting to business of 250 billion rupees with major crops such as soyabean (61%), maize (32%), cotton (11%), canola (5%), Papaya(1%)

12 Examples of Some GM crops : Example Institution Altered trait of GM Canola (Oilseed Monsanto/ Calgene Altered oil composition high lauric acid (for expanded use of rapeseed oil in soap and food products Crops) Corn Monsanto Resistance to corn borer (Bt) Corn Hoechst/AgrEvo/PGS -do- Corn Novartis -do- Corn Mycogen -do- Corn Novartis/Northrup -doking Corn Monsanto/DeKlab Resistance to corn borer (Bt) Corn Monsanto Resistance to herbicide glyphosate and to corn borer (Bt) Corn Monsanto/Deklab Resistance to herbicide glyphosinate Corn Hoechst/Agro Evo. -do- Corn Hoechst/Agr Male sterility/resistance to herbicide glyfosinate Evo/PGs Cotton Monsanto/calgene Resistance to horbicide bromoxynil Rhone /Poulenc Cotton Dupont Resistance to herbicide sulfonyl urea Cotton Monsanto Resistance to bollworm and budworm (Bt) Cotton Monsanto Resistance to herbicide glyphosate Cotton Monsanto/Calgene/R hone Poulenc Resistance to herbicide bromoxynil bollworms and budworms.

13 What are the environmental benefits of GM crops? One of the significant environmental benefits of CM crops is the dramatic reduction in pesticide use, with the size of the reduction varying between crops and introduced trait. *In 2000, total global reduction in pesticide use was estimated of 22.3 million kg of formulated product as a result of using herbicide tolerant CM soybean, seed rate, cotton and corn varieties and insect protected CM cotton; the deployment of insect- resistant Bt varieties was estimated to have reduced the total world use of insecticides by 14%. *In the USA, adoption of CM crops resulted in pesticide use reduction of 45.6 million pounds in 2001

14 Use of Bt cotton in China has led to an 80% reduction in the use of foliar insecticides and an estimated 15,000 tons reduction in pesticide use *Herbicide tolerant soybean farmers in North America are able to spray less to control weeds and use no-till or conservation-till cultivation systems *Reduced use of pesticides can significantly decrease their effects on water quality through runoff and leaching of residues into surface and groundwater. For example, run-off water from US fields planted with Bt cotton was virtually free of Insecticides during a four-year US Department of Agriculture study

15 GM crops can significantly Improve crop yields, so that more food can be grown on less land area. For example, in the US, 3.5 billion pounds of corn were gained from the 2001 harvest alone *Bt maize adoption in Spain resulted in yield increases of 6.3% orl average, or a net increase of more than 800 kg/ha. Farmers also experienced savings on pesticide use by Euro 24 to Euro 102/ha *Adoption of Bt corn in the Philippines led to pesticide cost reduction of as much as 56%.

16 Risks for agriculture Weed or super weeds Alternation of nutritional value Reduction of cultivars and loss of biodiversity Risks of interaction with non-target organisms Genetic pollution through pollen or seed dispersal Horizontal gene transfer Transfer of foreign gene to micro-organisms Via DNA uptake Generation of new line viruses by recombination General concerns higher cost of agriculture Loss of familiarity Ethical issues etc.

17 Biosafety aspects of GMO. a) Risks to human health Toxicity and food quality/safety Allergies Resistance of Pathogen/Antibiotic resistance b) Risks for environment Persistence of gene or transgene or transgene products Resistance of target organisms/susceptibility of non-target organisms Increased use of chemicals in agriculture Transgene instability Unpredictable gene expression

18 How are GM crops assessed for environmental safety? GM crops are thoroughly evaluated for environmental effects before entering the marketplace. They are assessed by many stakeholders in accordance with principles developed by environmental experts around the world. Among those who conduct risk assessment procedures are the developers of GM crops, regulatory bodies, and academic scientists.

19 Most countries use similar risk assessment procedures in considering the interactions between a GM crop and its environment. These include information about the role of the introduced gene, and the effect that it brings into the recipient plant. Also addressed are specific questions about unintentional effects such as:

20 Impact on non-target organisms in the environment, - whether the modified crop might persist in the environment longer than usual or invade new habitats - likelihood and consequences of a gene being transferred unintentionally from the modified crop to other species In addition to performing pre-commercialization tests for environmental safety, every GM crop should also be subjected to post approval monitoring by the product developer, independent researchers, and Government scientists. This helps ensure that biotech crops continue to be safe for consumers and the environment

21 Strategy for developing herbicide resistance Genes that encode such target molecules that are insensitive to herbicide are used. Target protein is over produced A pathway is introduced that detoxifies the herbicide. Example : Transgenic petunia resistant to glyphosate were developed by transfer of a gene ecoding EPSPS (5 enolpyruryl-shikimate-3 phosphate-synthatase) that over produces the enzyme. This overproducing gene was isolated from plants selected for herbicide resistance. 1) Target molecules that are insensitive to herbicide Example Engyme Source Gene aro A EPSPS Salmonella typhimurium ALS (Actolactate E. coli synthatase) Mutant tobacoo or (Leucine, Arbidopsis (Tolerates Isoleucine, valine) sulphonyl urea herbicide)

22 Sl.No. Mechanisms of action of selected herbicides and bases of generating resistance against them in transgenics Active principles of herbicide Inhibition of Target protein I Amino acid biosynthesis inhibitors 1. Glyphosate (Roundup) Aromatic amino acid ESPS 2. Sulphonylurea and Imidazolnones 3. Phosphinothri cin (Basta) biosynthesis Branched chain amino acids Glutamine biosynthesis Acitolacetate synthase (ALS) Glutamine synthese Herbicidal action Proved sepectrum Selective Broadspectru m sptreptomyces Basis of resistance Over expression of EPSPS gene, aro A gene from Ecoli, Salmonella (insensitive to EPSPS) Mutant of Als gene from tolerance Arabidopsis bar gene from (detoxi fication) II Photosynthesis inhibitors 4. Atrazine (Lassso) Photosystem II OB (32kDa ) Protein Selective Mutant PSb A gene gluta thionedetermination) 5. Bromozynil (Buctril) Photosynthesis - Selectivw Bbxngene from Klebsislla.

23 Mode of action Bacterial crygene produces cry protein ingested by insect on feeding - gets dissolved in alkaline juices present in midgutlumen - gut proteases process them hydrolytically to release core toxic fragments Toxic fragments get attached to specific receptors present in the brush boarder of epithelial cells of midgut. Other insect resistance genes Several insect pests are not susceptible to the currently available cry proteins. For such insects alternative insecticidal proteins are needed. Example : Inhibitors of digestive enzymes Cowpea trypsin inhibitor (CpTI) Serine protease inhibitor (aprotinin). Cystein protease inhibitor Proteinase inhibitor II Lectins These genes have been transferred into some explants and they show resistance against Members of Lepidoptera and coleoptera.

24 Why Herbicide resistance Biodegradable herbicides are desirable in view of environmental concerns. Some of the biodegradable herbicides are non-selective. This has necessitated the development of crop plants resistant against these herbicides. Effect of herbicide : Affect process like photosynthesis Affect biosynthesis of essential amino acids and thus cause death of the target plants

25 GM crops with insect resistance Insect resistant plants contain either a gene from the bacterium Bacillus thuringiensis or the cowpea trypsin inhibitor gene. Examples (Cry gene of Bacillus thuringiensis) Gene Bacterial strain Target Cry1A (a) HD 1 Lepidoptera Cry 1A (b) Berliner 1715 Lepidoptera Cry 1/B HD 2 Lepidoptera Cry 1C HD 110 Lepidoptera Cry 1D HD 68 Lepidoptera Cry 1E HD 146 Lepidoptera Cry 11A HD 263 Lepidoptera and Diptera Cry IIIA Tenebrionis Coleoptera Cry III B Tolworthi Coleoptera Cry IIIC Gallariae Coleoptera

26 PUBLIC AWARENESS Awareness Camp Preparation of IEC Material In regional language interaction Focus Group discussion (NGOs, Scientists & Farmers) Training Display of Seminar documentary & films Symposium Exposure visits Mass Media Radio TV Printed media Road side Folk Programme N.B. IEC material (Information, Education, Communication) includes booklets, leaflets, folders, charts, posters hoardings)

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