GROUP II Molecular Bio Presentation

8/2/2019 GROUP II Molecular Bio Presentation

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APPLICATION OF MOLECULARBIOLOGY IN AGRICULTURE

GROUP II

MPAKA PETER

MUHWEZI OBEDKALEMBE SOLOME



DEFINITIONS

• Molecular biology: The branch

of biology that deals with the

formation, structure, and

function of macromoleculesessential to life, such as

nucleic acids and proteins, and

especially with their role in cell

replication and the

transmission of genetic

information.

• Agriculture: The science,

art, or occupation

concerned with cultivating

land, raising crops, and

feeding, breeding, and

raising livestock.



INTRODUCTION

• Application of molecular biology in agriculture dates way back to at

least 10000years.

• Humans have constantly searched for improved varieties of their

crop plants and animals.

• Gene cloning in animals has been on going, knowingly or

unknowingly

• The rate of evolution of new species through natural selection was

slow, but now molecular methods like gene cloning have been

discovered that can help fasten the process



Plant agriculture

Objectives

• To have varieties with better nutritional qualities

• Higher yields

• Crops that aid cultivation and harvesting

• Crops which are pest resistant

• To understand plant evolution



GENE CLONING

This is the insertion of a fragment

of DNA, carrying a gene, into a

cloning vector and subsequent

propagation of the

recombinant DNA molecule in

the host organism.

Ways

• Gene addition

• Gene subtraction



GENE ADDITION

• Alters the characteristics of

a plant by provision of one

or more new genes

Applications :

Plants that make their own

insecticides

• Herbicide resistant crops

• Modified fruit ripening

• Drought tolerance

• Improved sweetness

• Improved flower colour

• etc



Plants that make their own insecticide

• Plants can be attacked by bacteria, viruses,

fungi and animals: large scale destruction is by

insects.

• Insecticides are normally used to reduce crop

damage but they are non specific, toxic and

insects can evade them



The δ-endotoxin of Bacillus

thuringiensis

• Bacteria are prey to insects and have a defense mechanism against

insects.

• e.g. B. thuringiensis produces δ-endotoxin that is highly poisonous

than insecticides

• Molecular biologists have taken advantage of this toxin to help in

self crop protection.

• By introduction of the gene that codes for the δ-endotoxin into a

plant.



Cloning of δ-endotoxin gene in maize



FINDINGS• The factors assessed were damage to foliage and length of tunnels

produced by the larvae boring into the plant.

• Transformed plants showed better results than the non modified.

Eg length of tunnels reduced from 40.7cm to 6.3cm



Other applications of gene addition



Gene subtraction

• The unwanted gene is inactivated

• Strategies are several but the best is use of

antisense RNA

• This has been used to delay tomato ripening

• The gene that codes for polygalacturonase

enzyme,responsible for ripening is inactivated.



GRAPH

Expression in a normal plantComparison: expression innormal and modified plant



Other Applications Of Gene

Subtraction



Genetic modification in animals

Why ?

• Scientific and medical research

• Treatment of human disease

• Production of modified food producing

animals



Genetic modification of animals ctd

How?

• Four steps involved in gene transfer

I. Identification of a gene with a significant and desired effects

II. Introducing the DNA fragment coding for the desired gene

III. Regulating the expression of the introduced gene

IV. Confirming transmission of the transferred gene to the next

generation of animals



Limitations

•Escape genes

• Poor produce due to target

pests resistance

• Possible harmful effect of

the marker genes used with

plant cloning vectors

• Terminator technology

•Disruption of the farmland

biodiversity

• ethical issues arise:-moral,

religious etc

• It is expensive

• Un expected yet undetected

mutations can alter the

future in unpleasant ways

f l l b l



Future of molecular biology in

agriculture •

Transgenic plants are being used in pharmaceutical industries toproduce many therapeutic proteins, including antibodies, blood

products, cytokines, growth factors, hormones, recombinant

enzymes and human and veterinary vaccines (Twyman et al , 2005).

• Several PDP products for the treatment of human diseases are

approaching commercialization, including recombinant gastriclipase for the treatment of cystic fibrosis, and antibodies for the

prevention of dental caries and the treatment of non-Hodgkin's

lymphoma (Ma et al , 2003).

• There are also several veterinary vaccines in the pipeline.

http://www.ncbi.nlm.nih.gov/pubmed/15757412















Future of molecular biology in

agricultureProduct Class Indication Company/Organiza

tion

Crop Status

Various singlechain

Fv antibody

fragments

Antibody Non-Hodgkin's

lymphoma

Large Scale Biology

Corp

Viral vectors in

tobacco

Phase I

CaroRx Antibody Dental caries Planet Biotechnology

Inc.

Transgenic tobacco Phase II

E.coli heatlabile

toxin

Vaccine Diarrhoea Prodigene Inc. Transgenic maize Phase I

Gastric lipase Therapeutic enzyme Cystic fibrosis,

pancreatitis

Meristem

Therapeutics

Transgenic maize Phase II

Hepatitis B Virus

surface antigen

Vaccine Hepatitis B Arntzen group

(Richter et al, 2000)

Transgenic potato Phase I

Thomas Jefferson

University/Polish

Academy of Sciences

Transgenic lettuce Phase I

Human intrinsic

factor

Dietary Vitamin B12

deficiency

Cobento Biotech AS Transgenic

Arabidopsis

Phase II

Lactoferrin Dietary Gastrointestinal

infections

Meristem

Therapeutics

Transgenic maize Phase I

Norwalk virus capsid

protein

Vaccine Norwalk virus

infection

Arntzen group

(Tacket et al, 2000)

Transgenic potato Phase I

Rabies glycoprotein Vaccine Rabies Yusibov et al (2002) Viral vectors in Phase I






















References

• http://www.ncbi.nlm.nih.gov/pmc/articles/P

MC26347/

• http://findarticles.com/p/articles/mi_hb1366/

is_1_15/ai_n29297863/

• T.A brown () gene cloning and DNA analysis 6th

edn

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC26347/


http://findarticles.com/p/articles/mi_hb1366/is_1_15/ai_n29297863/






GROUP II Molecular Bio Presentation

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