Teknik rekayasa genetika memungkinkan manusia untuk menghasilkan tanaman yang termodifikasi secara genetik atau disebut dengan GMO (genetically modified organism). Teknik rekayasa banyak dilakukan pada tanaman pertanian, seperti: padi, jagung, kacang hijau, dan lain-lain. Modifikasi gen atau manipulasi gen dapat dilakukan dengan beberapa teknik: a. Insersi gen dengan sifat yang diinginkan dari satu organisme ke organisme lain sehingga dihasilka organisme transgenik. Salah satunya dengan bantuan Agrobacterium tumefaciens. b. Perubahan gen-gen yang ada pada organisme yang mengakibatkan perubahan ekspresi gen

1. AGROBACTERIUM
A UNIQUE BACTERIAL
SPECIES GEN
TRANSFER TO PLANT
FITRI DAMAYANTI

2. METHODS OF DELIVERING DNA INTO PLANT CELLS
BIOLOGICAL:
❑ Agrobacterium
❑ Other bacteria
❑ Viruses
PHYSICAL:
❑ Particle bombardment
❑ Electroporation
❑ Carbon nanofibers

3. TRANSFORMATION OVERVIEW
http://www.ag.ndsu.edu/pubs/plantsci/crops/a1219-2.gif

4. AGROBACTERIUM
❑ Infects plants by introducing new DNA
❑ Integrates DNA into plant genome
❑ Several species that have this ability
❑ Very useful for genetic modification of plants
❑Causes hairy root disease instead of crown gall
❑DNA transfer occurs without two essential proteins
(VirE1 and VirE2) found in Agrobacterium tumefaciens

5. AGROBACTERIUM
Agrobacterium tumefaciens:
❑ The Gram-negative soil bacterium as pathogen
results in crown gall tumors in plants
❑ T-DNA, a part of the bacterial tumor-inducing (Ti)
plasmid, is transferred from the bacterium to the
plant cell with a number of Virulence (Vir) proteins
encoded by the Ti-plasmid
Agrobacterium rhizogenes:
Root inducing (Ri) plasmid

6. CAUSAL AGENT OF CROWN GALL DISEASE
microbewiki.kenyon.edu/index.php/Agrobacterium
http://pubs.caes.uga.edu/caespubs/pubcd/images/B1286-17.jpg

7. ONLY KNOWN NATURAL EXAMPLE OF DNA TRANSPORT BETWEEN KINGDOMS
1. (Virulent) strains of A.
tumefaciens contain a 200-kb
tumor inducing (Ti) plasmid
2. Bacteria transfer a portion of
the plasmid DNA into the
plant host (T-DNA).

8. AGROBACTERIUM TUMEFACIENS PLANT INFECTION AND TRANSFORMATION
Ti plasmid T-DNA Region
T-DNA
integrated
into plant
genome
Bacterial
Cell
Plant Cell

9. OVERVIEW OF THE INFECTION PROCESS

10. AGROBACTERIUM/PLANT INTERACTIONS
opines
Agrobacterium at
wound site transfers
T-DNA to plant cell.
Agrobacterium in soil use
opines as nutrients

11. MOST PLANTS STILL NEED TISSUE CULTURE FOR TRANSFORMATION AND REGENERATION

12. ALTERNATE METHODS OF TRANSORMING PLANTS: PARTICLE BOMBARDMENT
Gen gun

13. ALTERNATE METHODS OF TRANSORMING PLANTS: PARTICLE BOMBARDMENT
1. DNA- or RNA-coated gold/tungsten particles are loaded into the
gun and you pull the trigger
2. A low pressure helium pulse delivers the coated gold/tungsten
particles into virtually any target cell or tissue
3. The particles carry the DNA → cells do not have to be removed
from tissue in order to transform the cells
4. As the cells repair their injuries, they integrate their DNA into their
genome, thus allowing for the host cell to transcribe and translate
the transgene