1) Vector-mediated transformation:
- Agrobacterium (Agrobactreium tumefaciens and Agrobacterium rhizogenes) is a soil bacteria with T-DNA that are transfer to the crops during infection.
- T-DNA carries genes for phytohormones which are liable for the multiplication of cells, establishing of crown gall and nutrients (opines) in plant cell.
- In genetic modification this genes are substituted with targeted genes.
- Attainable as in the transfer of DNA, only the 25 bp T-DNA border sequences on the left and right border are required.
- Advantages: Only one or few genes and large part of DNA is transferred with minimal rearrangements.
2) Direct gene transfer:
2.1 Protoplasts transformation:
- Involve the uptake of DNA into plant cells with cell wall that has been enzymatically digested.
- Using polyethylene glycol (PEG –ransformation)/electric pulses (electropoation).
- Advantages: Independence technique.
2.2 Particle bombardment:
- Involve the transfer of DNA into plant cells by penetrating high speed DNA coated microprojectile through the cell wall and cell membrane.
- Microprojectile is sufficiently fine enough and equipped with the required mass to penetrate plant cell without causing too much damage.
- Advantages: Compatible to all organism
- Disadvantages: Possibility of complicated insertion loci that lead to gene silencing.
- Agrobacterium (Agrobactreium tumefaciens and Agrobacterium rhizogenes) is a soil bacteria with T-DNA that are transfer to the crops during infection.
- T-DNA carries genes for phytohormones which are liable for the multiplication of cells, establishing of crown gall and nutrients (opines) in plant cell.
- In genetic modification this genes are substituted with targeted genes.
- Attainable as in the transfer of DNA, only the 25 bp T-DNA border sequences on the left and right border are required.
- Advantages: Only one or few genes and large part of DNA is transferred with minimal rearrangements.
2) Direct gene transfer:
2.1 Protoplasts transformation:
- Involve the uptake of DNA into plant cells with cell wall that has been enzymatically digested.
- Using polyethylene glycol (PEG –ransformation)/electric pulses (electropoation).
- Advantages: Independence technique.
2.2 Particle bombardment:
- Involve the transfer of DNA into plant cells by penetrating high speed DNA coated microprojectile through the cell wall and cell membrane.
- Microprojectile is sufficiently fine enough and equipped with the required mass to penetrate plant cell without causing too much damage.
- Advantages: Compatible to all organism
- Disadvantages: Possibility of complicated insertion loci that lead to gene silencing.
References: Susanne Stirn and Horst Lor. 2003. Genetically Modified Plants. In: Knut J. Heller. Genetically Engineered Food. Germany: WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 26-27
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