17 agrobacterium tumefaciens
TRANSCRIPT
![Page 1: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/1.jpg)
Agrobacterium tumefaciens
Nature’s little plant transformer
Rhizobium radiobacter
![Page 2: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/2.jpg)
Definition of termsO vir genes- essential for the excision and transport of
the T-DNA to the wounded plant cell. O Cytokinin-plant hormone for cell plant division and
tumorous growthO Auxin-another plant hormone (inducing stem and
leaf elongation, inducing parthenocarpy and preventing aging)
O Opines- a class of chemicals that serve as a source of nitrogen for A. tumefaciens, but not for most other organisms.
![Page 3: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/3.jpg)
O Acetylsyringone - produced by wounded plant cells (phenolic compound).
-plays a further role in the infection process, because at higher concentrations it activates the virulence genes (Vir genes) on the Ti plasmid
![Page 4: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/4.jpg)
Agrobacterium tumefaciensO rod-shaped, Gram-negative soil bacterium
O causes crown gall disease, especially members of the rose family such as apple, pear, peach, cherry, almond, raspberry and roses.
![Page 5: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/5.jpg)
![Page 6: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/6.jpg)
![Page 7: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/7.jpg)
A.Tumefaciens gall is not a tiny thing
![Page 8: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/8.jpg)
O Tumor formation is the result of the transfer, integration and expression of genes on a specific segment of A.Tumefaciens plasmid DNA called the T-DNA. *
O Tumor-inducing plasmidAgrobacterium Mechanism.mp4
![Page 9: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/9.jpg)
O This disease is one of the most widely known, because of its remarkable biology.
O Basically, the bacterium transfers part of its DNA to the plant, and this DNA integrates into the plant’s genome, causing the production of tumours and associated changes in plant metabolism.
O Agrobacterium Mediated Transformation.mp4
![Page 10: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/10.jpg)
DNA between L and R borders istransferred to plantas ssDNA;
T-DNA encoded genes can be substituted by target genes
![Page 11: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/11.jpg)
Key steps from natural Agrobacterium to “useful” Agrobacterium
O Some vir genes deleted--disarmedO Opines not going to be producedO Deleting tumorogenesis function
O Choosing strains that transfer DNA in labO Clone in genes of interest, antibiotic resistance
genes, etc.
O Agrobacterium Mechanism.mp4
![Page 12: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/12.jpg)
Agroinfiltration-transient method of expressing transgenes
![Page 13: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/13.jpg)
Agroinfiltration—forcing Agrobacterium with transgenes into leaves
![Page 14: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/14.jpg)
Agroinfiltration--tobacco
![Page 15: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/15.jpg)
![Page 16: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/16.jpg)
Application
![Page 17: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/17.jpg)
OInsect resistance
ODisease resistance
OAbiotic stresses
OHerbicide Tolerance
![Page 18: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/18.jpg)
Environmental and biosafety aspects
OEnvironmental release and biosafety have been subjects of debate regarding transgenic plants, especially for food crop like rice.
ODemand for marker-free transgenic plants is high.
![Page 19: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/19.jpg)
Summary
![Page 20: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/20.jpg)
Agrobacteria are biological vectors for introduction of genes into plants.
• Agrobacteria attach to plant cell surfaces at wound sites.
• The plant releases wound signal compounds, such as acetosyringone.
• The signal binds to virA on the Agrobacterium membrane.
• VirA with signal bound activates virG.
![Page 21: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/21.jpg)
• The T-DNA is transferred to the plant cell, where it integrates in nuclear DNA.
• T-DNA codes for proteins that produce hormones and opines. Hormones encourage growth of the transformed plant tissue. Opines feed bacteria a carbon and nitrogen source.
![Page 22: 17 agrobacterium tumefaciens](https://reader033.vdocuments.mx/reader033/viewer/2022061609/55c0cf6ebb61eb9c758b4602/html5/thumbnails/22.jpg)
Thank you!!!