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Genetically modified Crops. Prof. (Mrs) Krishna Misra IIIT-Allahabad 16 th April, 2012. WHAT IS GENETIC MODIFICATION. Individual characteristics of plants, such as the height, the shape and colour of flowers, are determined by their genes.
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Genetically modified Crops Prof. (Mrs) Krishna Misra IIIT-Allahabad 16th April, 2012
WHAT IS GENETIC MODIFICATION • Individual characteristics of plants, such as the height, the shape and colour of flowers, are determined by their genes. • These characteristics, or traits, are inherited from generation to generation. • Genetic modification (GM) involves copying the genes responsible for a particular trait from one organism, and transferring them to another.
Genetic Engineering The simple addition, deletion or manipulation of a single trait in an organism to create a desired change
Some examples of G.E. Insertion of human genes into sheep so that they secrete alpha-1 antitrypsin in their milk - a useful substance in treating some cases of lung disease. creating a chicken with four legs and no wings. creating a goat with spider genes that creates "silk" in its milk.
One language of life Human genes work in bacteria Monkey genes work in mice and earthworms. Tree genes work in bananas Frog genes work in rice. There is no limit in theory to the potential of genetic engineering Genetic engineering has given us the power to alter the very basis of life on earth.
What is a genetic code? • In each gene there is a piece of genetic information which guides our growth and is in the form of a chemical code, called the genetic code • The genetic code in the DNA, is virtually identical across all living organisms and is like a recipe book for the body to make proteins • The DNA code is made up of very long chains of four chemical ‘letters’: Adenine (A), Guanine (G), Thymine (T) and Cytosine (C) • In the DNA information, each ‘word’ is a combination of three of these four chemical ‘letters’ A, G, C and T • Each three-letter word (triplet) tells the cell to produce a particular amino acid that form proteins • The sequence of three-letter words in the gene enables the cells to assemble the amino acids in the correct order to make up a protein • Different genes are active in different cell types, tissues and organs, producing the necessary specific proteins; some genes are ‘switched off’ and others are ‘switched on’ • Changes to the genetic code can mean that a particular protein is not produced properly, produced in the wrong amounts or not produced at all • In some cases, the change in the genetic code can result in a genetic condition, affecting the growth and traits of the organism
Using Restriction endonucleases desired DNA fragments (Genes) are obtained
Example of a genetically modified crop Bt protein kills corn borer insect Maize genetically modified to Bt protein maize Bt maize has been genetically modified to make it produce a protein from the bacterium Bacillus thuringiensis. This protein kills the corn borer insect which, in other countries, is a major threat to maize crops
How a fish antifreeze gene is added to a tomato? Scientists have created a frost-resistant tomato plant by adding an antifreeze gene from a cold-water fish to it. The antifreeze gene comes from the cold-water flounder, a fish that can survive in very cold conditions. This is how it was done.
The antifreeze DNA is joined to a plasmid DNA and this combination of two DNA’s from different sources is known as recombinant DNA The recombinant DNA, including the antifreeze gene, is placed in a bacterium. The antifreeze DNA is joined onto a piece of DNA called a plasmid. This hybrid DNA, which is a combination of DNA from 2 different sources, is known as recombinant DNA.
The bacterium is allowed to reproduce many times producing lots of copies of the recombinant DNA. • Tomato plant cells are infected with the bacteria. As a result, the antifreeze gene in the plasmid, in the bacteria becomes integrated into the tomato plant cell DNA. • Tomato cells are placed in a growth medium that encourages the cells to grow into plants.
Tomato plant seedling is planted. This GM tomato plant contains a copy of the flounder antifreeze gene in every one of its cells. The plant is frost resistant, therefore the fish gene still works.
DIFFERENCES BETWEEN CONVENTIONAL BREEDING AND GENETIC MODIFICATION ? Conventional Breeding With conventional breeding, traits can only be transferred between plants or animals of the same or closely related species. This method takes lot of effort and is not precise GM Technique GM enables traits to be transferred between different species, and potentially even between animals and plants This method is precise
Why produce GM Crops? (Benefits) • To strengthen the resistance against weeds and pests • To cope better with climatic changes • To improve the quality of products • To improve food production to feed the world • To minimize the cost of production • To minimize crop injury • To minimize loss during transport and storage
Herbicide Resistance • Herbicide like isoproturon is used to eliminate Phalaris minor , a weed growing along with wheat which decreases the yield of the latter *. • However, herbicides do become resistant after continued use due to genetic mutation. • Scientists insert the herbicide resistance genes via agrobacterium into food plants so that they will not be affected by the herbicide. * 1. Singh DV, Agarwal S, Kesarwani RK & Misra K “Molecular Modeling and Computational Simulation of Photosystem-II Reaction Centre to Address Isoproturon Resistance in Phalaris minor”J Mol Mod 2011, ISSN: 1610-2940 (Accepted 9/1/2012) DOI: 10.1007/s00894-012-1386-3 2. Singh DV, Adeppa K, Misra K Mechanism of isoproturon resistance in Phalaris minor: In silico design, synthesis and testing of some novel herbicides for regaining sensitivity Journal of Molecular Modeling,Volume 18, Issue 4 (2012), Page 1431-1445 ; publication date 14-7-2011; http://dx.doi.org/10.1007/s00894-011-1169-2
Pest resistance • Scientists have inserted the toxin producing gene from Bacillus thuringienus, a soil bacterium, into maize producing (Bt maize) , brinjal (Bt brinjal) and cotton (Bt cotton) etc. • Destructive insects get killed when eating the crop. • The loss due to destructive insects is greatly reduced.
Controversies regarding GM foods • Will it affect our health? • Will it affect the eco-system? • Will it have harmful side-effects? • Will it reduce consumer choices? • Will we suffer from toxins produced? • Will we inherit the toxin-producing genes? • Will it cause allergic reactions?
Will GM food incur health problems? • GM food is consumed as DNA molecules. • As human body has been coping perfectly well with foreign DNA for millions years. No harm is proved at this moment. without GM Food With GM food
Will GM technology prove harmful to eco-system? • Will it affect the growth of other plants? • Will living things lose their living environment? • Will it create strange species?
Any possible side-effects? • Will genes used to modify crops jump the species barrier? • Can the possible DNA mutation be controlled? • Possibility of superbug creation?
Religion and choice? • What happens if vegetarians eat food which is genetically engineered with an animal gene? • Will it repel choice of food?
Suggested Solutions… • Add labels to the packages to make public aware • Improvement of Genetic Engineering technology with time may solve many queries • Regular food tests may be performed
HOW TO DEAL WITH GM FOOD AS CONSUMERS? • Acquire awareness about environment • Raise environmental protection attitude and practice • The change of attitude, can help to keep a positive heart towards GM Food.
The Global Scenario (Why US leads in GM Crop Technology) In mid 80’s US National Science Academy, The Ecological Society of America, American Society for Microbiology and the Crop Science Society of America advised their government about GM food. A conference was held in California in 1975 where a set of voluntary code of conduct was formed which later came to be known as rDNA guidelines of NIH (National Institute of Health)and was adopted globally. However, US A has during last December deregulated Monsanto’s Vistive R Gold Soyabeans and drought tolerant corn based on scientific evidences.
The Indian Scenario • The present regulatory system in India is like a boat without radar • In India scientific community is giving mild statements under duress. • It is high time science academies should come together to take lead and lobby the government and parliament to set a proper agenda for the nation. National academy of sciences,India (NASI) has already initiated the process. • At present some vocal activists without any knowledge of modern science are misleading media, politicians and policy makers creating public scare. • As a result many states have declared themselves GM free. Rajasthan is not even allowing field testing. • The Indian scientific community has a challenging task at hand. Scientists , specially in key positions must become bold and convey their views to media and public and dispel the scare created by non-scientist activists. • The situation is very volatile and needs immediate attention.
A message from Dr HS Gupta, Director IARI , New Delhi • It is high time, we the scientists , National Academies and Scientific Societies make a concerted effort to educate the policy makers about GM technology and its benefits. • Also we must tell them about USA’s deregulation of GM Soyabean and drought tolerant corn. If we miss the opportunity, nation will be deprived of this technology for a long time. • We have a new minister of environment and forest who might be willing to hear from the scientific community. Let us do something positive and concrete.
