Binary Vector, By KK Sahu sir

Introduction
Components of binary vector
Development of binary vector system
Properties of binary vector
Types of binary vector
Plant transformation using binary vector
Advantage of using binary vector
Conclusion
References

1. BINARY VECTOR By KAUSHAL KUMAR SAHU Assistant Professor (Ad Hoc) Department of Biotechnology Govt. Digvijay Autonomous P. G. College Raj-Nandgaon ( C. G. )

2. SYNOPSIS Introduction Components of binary vector Development of binary vector system Properties of binary vector Types of binary vector Plant transformation using binary vector Advantage of using binary vector Conclusion References

3. INTRODUCTION In these systems, the T-DNA region containing a gene of interest is contained in one vector and the vir region is located in a separate disarmed (without tumor-genes) Ti plasmid. The plasmids co-reside in Agrobacterium and remain independent . In the binary vector system, the two different plasmids employed are: a wide-host-range small replicon , which has an origin of replication ( ori ) that permits the maintenance of the plasmid in a wide range of bacteria including E. coli and Agrobacterium . a helper Ti plasmid , harbored in A. tumefaciens , which lacks the entire T-DNA region but contains an intact vir region.

4. COMPONENT OF BINARY VECTOR The standard component of binary vector are:  Multiple cloning site A broad host range origin of replication functional in both E.coli and A. tumefaciens . Selectable markers for both bacteria and plants T-DNA border sequences.  

5. DEVELOPMENT OF BINARY VECTOR   Hoekema et al. (1983) and de Framond et al. (1983) determined that the  vir  and T-DNA regions of Ti-plasmids could be split onto two separate replicons . 

6. Genes of interest are maintained within the T-DNA region of a binary vector. Vir proteins encoded by genes on a separate replicon ( vir helper) mediate T-DNA processing from the binary vector and T- DNAtransfer from the bacterium to the host cell. The selection marker is used to indicate successful plant transformation. ori , Origin of replication; Abr , antibiotic-resistance gene used to select for the presence of the T- DNAbinary vector in E.Coli or in Agrobacterium .

7. PROPERTIES OF BINARY VECTOR These include the following: T-DNA left and right border repeat sequences to define and delimit T-DNA. A plant-active selectable marker gene . Restriction endonuclease , rare-cutting, or homing endonuclease sites within T-DNA into which goi can be inserted. Origin(s) of replication to allow maintenance in E. coli and Agrobacterium . Antibiotic-resistance genes within the chromosome and within backbone sequences for selection of the binary vector in E. coli and Agrobacterium .

8. TYPES pGA series vectors pCG series vectors pCIT series Pgptv pBECK2000 series pGreen series

9. PLANT TRANSFORMATION USING BINARY VECTOR Propagate binary vector in E. coli Isolate binary vector from E.coli and engineer (introduce a foreign gene) Isolate engineered binary vector and introduce into Agrobacterium containing a modified Ti plasmid Infect plant tissue with engineered Agrobacterium (T-DNA containing the foreign gene gets inserted into a plant cell genome)

10. Advantages of using Binary vector   Binary vector do not need in vivo recombination. Binary vectors require only that an intact plasmid vector to be introduced into the target bacterium, making the process of bacterial transformation both more efficient and quicker. Binary vector systems with plant ready genes in Agrobacteria are easily and efficiently obtained. In binary system, the binary plasmids exist as separate replicons , thus copy number is not strictly tied to that of Ti plasmid.  

11. CONCLUSION T-DNA binary systems have greatly simplified the generation of transgenic plants. Along with companion vir helper strains, numerous different T-DNA binary vectors with specialized properties have been designed to facilitate such diverse activities as protein expression, activation tagging, protein localization, protein-protein interaction studies, and RNAi -mediated gene silencing.

12. REFERENCES MK Razdan and SS Bhojwani - Plant tissue culture H.S. Chawla - Introduction to plant biotechnology IK Vasil - plant cell and Tissue culture