Plant Tissue Culture: Focus

Plant Tissue Culture
Focus:
Introduction
History of plant Biotechnology
Plant Tissue Culture (Totipotency)
Stages of Micropropagation
Plant genetic engineering (Genetically engineered plants
and plant transformation)
GMO production.
Introduction
What is plant biotechnology?
• Plant biotechnology is a biological process to

produce a genetically modified plant by removing
genetic information from an organism, manipulating
it in the laboratory and then transferring it into a
plant to change certain of its characteristics.
• It mainly involves the introduction of foreign

genes into economically important plant species,
resulting in crop improvement and the production of
novel products in plants.
What is plant tissue culture?
• Tissue culture is the practice of growing plant
cells on artificial media.
• The other name for plant tissue culture is
micropropagation
• It involves the culture or growing of small pieces
of plant tissue.
• It is performed on artificial medium (nutrient
culture medium) under sterile conditions.
• Tissue culture is one of method for plant
propagation.
Totipotency
• Totipotent cell is a cell that is capable of
developing by regeneration into a whole
organism.
• Totipotency is the ability of a single cell to
express the full genome in the cells to which it
gives rise by cell division.
• Most plant cells have the ability to reproduce the
whole plant from single cells.
• Example of non-totipotency is human skin
cells are because human skin cells in culture
will divide to produce only more skin cells (not
nerve, muscle or other different cells).
Explant plant
Callus-a protective tissue,

consisting of parenchyma
cells, that can be
developed over a cut or
damaged pant surface OR
induced by hormone
Callus Shooting Rooting
Stage 1- Initiation of sterile explant culture
• Selection of explants (Initial pieces of the plant to start in vitro culture).
• Sterilization of tissue surface (to prevent contamination).
• Transfer of explants to nutrient media.
Stage 2 - Shoot initiation:

Medium
• Shoot multiplication from explants on nutrient media. transfer
Stage 3 – Root initiation :

• Root multiplication of root from explants on nutrient media.
Stage 4 – Acclimatization or hardening off

• The new plant removed from the in vitro environment.
• Transfer of plants to sterile soil or other substrate under controlled
conditions.
Stage 1 : Initiation of sterile ex-plant culture
1. Cleaning of the plant before removal of the
explant is usually accomplished by a brief
soaking in a bleach solution, followed by a
rinse in sterile water.
2. The cleaned explants (sterile explant) are
placed on agar medium (sterile medium) in
containers (glass bottles or test tubes).
Stage 2 and 3 : Shoot and Root initiation
• Hormones cytokinin (BAP) and auxin (NAA)
added in the tissue culture media will trigger the
growth of shoots and roots respectively.
Stage 4 : Acclimatization or hardening off
• The new plant removed from the in vitro condition
(in a sterile medium) transfer into sterile soil or
other substrate.
• The plants were grown under controlled condition
environments such as greenhouse.
Chemicals in plant cell cultures
• Basic plant cell culture media comprises of the
following chemical component:
1. Murashige and Skoog media (MS media)
containing both macro and micronutrients.
2. Vitamins (Thiamine, peridoxin, Nicotinic acid,
Biotin, Citric acid, Ascorbic acid, myo-inositol).
3. Hormones (Auxins and Cytokinins).
4. Energy source and carbon skeletons (Sucrose).
5. Gelling agent.
Murashige and Skoog media
Tissue culture media preparation steps
1. Sucrose is added with distilled water and was stirred

continuously.
2. Next, MS media solution, vitamins and hormones
were stirred continuously.
3. Next, the pH of media was adjusted to 5.0 – 7.0 using
NaOH and HCl.
4. Gelling agent such as agar was added and the mixture
was heated using microwave.
5. The media were poured into the conical or tissue
culture flasks.
6. The media flasks were sterilized using autoclave at
121oC , 15 p.s.i. for 15 or 20 minutes.
APPLICATION OF BIOTECHNOLOGY
IN AGRICULTURE
• Production of transgenic crop (genetically

modified plants/genetically modified
organisms)
• Produce through transfer/introduction of
foreign gene with desired traits (examples:
enhance nutrition, resistant towards pest,
tolerant towards herbicide, inducible vaccine)
into selected plants
• This technique is also known as recombinant
DNA technology
1. Genetic pesticides: Bt crops
• Bacillus thuringiensis (Bt) is a type of bacteria that

could produce crystallized (Cry) protein that kills
harmful insects and their larvae.
• Insects that ingested this protein will die in a very
short time.
• This is because B. thuringiensis is carrying Cry gene
which codes for Bt toxin that act as pesticides.
• The Cry gene had been successfully introduced into
tobacco, tomatoes, corn and cotton through DNA
recombinant technology.
2. Enhanced Nutrition : Golden rice
• Golden rice – rice that has been genetically modified

to produce a large amount of beta carotene (vitamin
A).
• The aim of golden rice is to end malnutrition and
hunger in third word countries.
• Golden rice is schedule to be grown in Uganda at the
year of 2020.
Golden rice and white rice
3. Delayed ripening: Flavr savr tomatoes
• Flavr-savr tomatoes were delayed-ripening

tomatoes, have superior flavor, color and texture; are
firmer for shipping and stay fresh longer.
• Ripening of tomatoes is caused by enzyme
polygalacturonase (PG), that is produced naturally
during decaying process. This enzyme will digest
pectin in wall of plant.
• Flavr-savr tomatoes were produced by removing PG
gene function.
Fruit ripening process
Pectin Fruit softening

polygalacturonase
Pectin X
polygalacturonase
X
Fruit softening
Fruit remains
hard
4. Herbicide tolerant crops
• Genetically engineered plants will have better

tolerant toward herbicide application. Thus only
weeds will be killed by herbicide.
5. Edible vaccine
• Antigens (hepatitis B) enter the bloodstream through

consuming plants (e.g. engineered banana), will trigger
the immune system to produce antibodies against it
(hepatitis B).

Plant Tissue Culture: Focus

Uploaded by

Copyright:

Available Formats

Plant Tissue Culture: Focus

Uploaded by

Document Information

Original Description:

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Plant Tissue Culture: Focus

Uploaded by

Copyright:

Available Formats

Plant Tissue Culture

• Plant biotechnology is a biological process to

• It mainly involves the introduction of foreign

Callus-a protective tissue,

Stage 2 - Shoot initiation:

Stage 3 – Root initiation :

Stage 4 – Acclimatization or hardening off

1. Sucrose is added with distilled water and was stirred

• Production of transgenic crop (genetically

• Bacillus thuringiensis (Bt) is a type of bacteria that

• Golden rice – rice that has been genetically modified

• Flavr-savr tomatoes were delayed-ripening

Pectin Fruit softening

• Genetically engineered plants will have better

• Antigens (hepatitis B) enter the bloodstream through

You might also like