GENETICALLY MODIFIED CROPS AND ITS FUTURE PROSPECTS

Genetically modified crops are plants with modified genome by the introduction of new gene or any DNA sequence of interest – a method called genetic engineering. Such crops are differently named as GMC or GM
crops or biotech crops etc. In January 1983, Monsanto Company in St. Louis, Missouri,
first developed transgenic plant. The first commercially grown genetically modified
food crop was a tomato created by California
Company in the early 1990s called the Flavr Savr, then came GM potatoes, modified with an insecticide gene taken from the snowdrop, were toxic to rats.

PROCESS OF DEVELOPING GM CROPS

The main steps involved in the development of GM crops are:

1. Insertion of the gene(s) into a transfer vector.  
2. Plant transformation. 
3. Selection of the modified plant cells. 
4. Regeneration into whole plants.  
5. Verification of transformation and characterization of the inserted DNA fragment. 
6. Testing of plant performance. 
7. Safety assessment.

METHODS OF GENE TRANSFER IN PLANTS

1. Vector-mediated or indirect gene transfer – Ti plasmid of Agrobacterium tumefaciens  is used as a vector.   

B. Vectorless or direct gene transfer – no vector use.

i) Chemical mediated gene transfer – PEG, dextran sulphate, Calcium phosphate  etc.

ii) Microinjection -  using fine tipped (0.5 - 1.0 µm diameter)glass needle or micropipette.

iii) Electroporation - a pulse of high voltage is applied.

iv)  Particle gun/Particle bombardment  - by a gun

v)  Liposome mediated gene transfer /Lipofection - 

 

 

APPLICATIONS OF Transgenic plants

A.  Stress tolerance

i)    Abiotic stress tolerance :

ii)   Herbicide tolerance : Glyphosate resistance

iii) Other abiotic stresses :

B.  Insect resistance

i)   Bt genes  transfer :

ii)  Cowpea trypsin inhibitor gene (CpTi)  transfer :

C.  Virus resistance 

D.  Resistance against Fungal and bacterial infections

E.  Delayed fruit ripening 

F.  Male Sterility  

G.  Production of biofuels 

H.  Improved shelf life 

I.   Production of useful by-products

i)  Drugs :

ii) Materials : 

J.  Bioremediation 

 

 

ADVANTAGES OF GMO CROPS

•          Less pesticide is needed to be used due to insect pest resistant.

•          They are more ecofriendly

•          Decrease in costs of growing and farming,

•          Higher crop yields.

•          Decrease in food prices due to lower costs and higher yield.

•          Scientific development of agriculture, health and related sciences.

•          Creation of “super foods” or New foods.

•          New products.

NEGATIVE IMPACTS OF GM CROPS

—  i) Test : The taste of GMOs are not as good or "natural".

—  ii) Environment : Unintended environmental impacts include harming non target and/or beneficial species in the case of crops with engineered insecticidal properties, as well as the development of new strains of resistant pests.

—  iii) Health : At present, there is no evidence to suggest that GM foods are unsafe. Some GMO crops causes allergy. Residual toxins resulting from introduced genes of the bacteria Bacillus thuringiensis in so called Bt crops are unlikely to harm humans.

—  iv) Markets : Due to controversy, GMO crops have less demand in the commercial market.

 

FUTURE PROSPECT OF GM PRODUCTS

Future envisaged applications of GMOs are diverse and include drugs in food, bananas that produce human vaccines against infectious diseases such as Hepatitis B, metabolically engineered fish that mature more quickly, fruit and nut trees that yield years earlier, and plants that produce new plastics with unique properties. While their practicality or efficacy in commercial production has yet to be fully tested, the next decade may see exponential increases in GM product development as researchers gain increasing access to genomic resources that are applicable to organisms beyond the scope of individual projects. Safety testing of these products will also at the same time be necessary to ensure that the perceived benefits will indeed outweigh the perceived and hidden costs of development.

CONCLUSION

Transgenic plants possess a gene or genes that have been transferred from a different species. Although DNA of another species can be integrated in a plant genome by natural processes, the term transgenic plants refers to plants created in a laboratory using recombinant DNA technology. The aim is to design plants with specific characteristics by artificial insertion of genes from other species or sometimes entirely different kingdoms. GM crops grown today, or under experimental development, have been modified with traits intended to provide benefit to farmers, consumers, or industry.