GeneTransfer in Plants
• Genetic transfer involves the removal of
gene from one species and inserting them
into another. This does not require sexual
• The new DNA remains stable and can
transmit the transferred gene to offspring ,
resulting in development of transgenic
• This transgenic plants carry this stable
integrated genes thus those plants obtained
through genetic engineering contain a gene
from and unrelated organ such genes are
called trans gene and those plants contain
them are called transgenic plants.
• The technique of introduction of foreign gene is
called genetic transformation .
• Gene transfer requires transgene and
i. Transgene : isolated genes of plants
viruses , bacteria etc.
ii. Targeted cells: culture cells ,protoplast
,pollens, zygots, and also cells from
• Overall process involves the following
stages for producing transgenic plant.
1. Gene transfer
2. Selection of transgenic plant
3. The recovery of transgenic plant
There are two methods
1.Vector mediated methods
2.DNA mediated gene transfer methods
Classification of gene transfer method
• Vectors are DNA carriers into which the genes are
inserted to make recombinant DNA
• Vectors along with this foreign genes are introduce
into appropriate host cells ,vectors are two types
1. Cloning vectors: This are use for making millions of
2. Expression vectors: This are use for expression of
clone gene to produce product
Vector mediated methods:
(A)Using Agrobacterium tumefaciens :-
• It is Gram-negative bacterium , commonly
occuring in soil. It Causes “ Crown gall
• On entering into plant through
mechanically wounded tissue site , it
causes tumerous outgrowth due to
proliferation of undifferentiated tissue .
Process of Gene Transfer :-
• By genetic transfer , the T1 Plasmids of
this bacterium can be modified to create
“Disarmed Plasmids ” , known as Vectors .
• These vectors can carry any DNA
A rumefaciens infected plant without
causing tumors growth .
• By placing foreign gene into T-DNA region
of the T1 plasmid , cloning of the
introduced gene is possible .
• Cloning of the required foreign DNA
sequence into vector using E-coli host is
• As plasmid resides inside bacteria ,
growing them on a medium leads to
simultaneous multiplication of bacteria
i. Improvement in both quality and quantity (yield) of crop.
ii. Development of herbicidal resistance
iii. Development of pesticidal resistance
iv. To produce valuable products
- Antigen and antibody production
- Vaccine production
- Oligopeptide and protein production
- Production of cyclodextrins
- Enzymes like anylase
APPLICATION OF GENETRANSFER::