rDNA Technology & Food Uses

Sana JavedUG 3- Section A

Recombinant DNA (rDNA) Technology

• Cutting a known DNA sequence from one organism & introducing it into another

• Recipient genotype ( & hence the phenotype) alteration

•

Food Safety

DNA insertion- uncontrolled event

Alterations in DNA may interfere with the regulation and expression of certain genes

• Toxins• Allergens• Nutritional change

Environmental Concerns

Escaping & spreading the engineered gene in the

natural gene flow process Insect resistant crops- Non-

specific

Ethical and Social Issues

• Prohibited animal-derived genes in plant foods

• Ecosystem disruption

Safety Assessment

• Conducted under ground rules given by WHO, FAO & OECD

Safety testing: • Toxicological testing• Allergenicity studies• Nutritional analysis

Environment: field allocation preventing horizontal gene transfer

Ethical concerns: labeling foods contai-ning animal-derived genes

Application of Recombinant DNA Technology in Agriculture

Adeena Shafique

INTRODUCTION

Application of recombinant DNA technology has primarily helped in producing three major types of transgenic plant having improved performances. These are:

(1) Development of stress tolerant plants(2) Development of plants having improved yield (3) Transgenic plants as a source of

biopharmaceuticals

Development of stress tolerant plant

• Plant resistant to environmental stress• Herbicide Resistant plant• Insect resistant plant• Disease resistance plant

Plants resistant to Environmental stress

• Abiotic stresses: Drought, Heat, Cold, Too salty or acidic soils

• Genetically modified Tomato and Canola tolerate very high salt levels.

• Maize and papaya resistant to aluminum.

Herbicide Resistant Plants

• Herbicide-RoundupTM contains glyphosate. • Glyphosate kills many plants. • It binds to the plant enzyme EPSP synthase.• rDNA technology modified EPSP gene.• Soybean resistant to glyphosate.

rDNA technology

Insect resistant plants

• Farmers can use insecticides but these are harmful for human health.

• Bt genes from Bacillus thuringiensis are used.• Transgenic crops (e.g. cotton, rice, maize,

potato, brinjal, cauliflower, cabbage etc.) with Bt genes have been developed and such transgenic varieties proved effective in controlling the insect pests.

Disease resistant plants

• Plants are susceptible to viral, bacterial, fungal diseases.

• Genes encoding viral coat protein expressed in plants. Protects the plant from subsequent infection.

• TMV coat protein gene expressed in tobacco plant protected it from TMV infection.

Development of plants having increased quality of plant products

Golden Rice

Increase in quality of plant products

• Golden rice containing beta carotene to overcome vitamin A deficiency in regions where rice is the staple food

• Canola containing high levels of oleic acids• Tomatoes which do not rot in room temperature • Other vegetables and fruits with delayed ripening

as well as modified flavor characteristics

Transgenic plant as a source of bio pharmaceuticals

• Edible vaccines- A reality in the future?!• Expression of antigenic proteins in crops like

banana and tomato.• Great advantages- avoiding storage problems,

easy delivery system, low cost.