Plant transformation vectors can be classified into cloning vectors, expression vectors, and integration vectors. Cloning vectors are small DNA molecules used to insert, store, and manipulate foreign DNA. Common cloning vectors include plasmids, bacteriophages, cosmids, and BACs/YACs. Expression vectors allow foreign DNA to be inserted and expressed in host cells. The Ti plasmid is often used as a plant expression vector due to genes that mediate DNA transfer to plant cells. Vector choice depends on desired DNA insert size, host system, and purpose of cloning/expression.

1. Plant transformation vectors

2. Transformation:
Transformation is the genetic alteration of cell resulting from the direct
uptake and incorporation of exogenous genetic material from its
surrounding.
Plant transformation:
Integration of DNA into plant genome by means other than fusion of
gametes.
Plant transformation consists of three step:
• Target gene
• Plant tissues
• Transformation methods

3. Vectors: Vector is one of the most element in recombinant DNA
technology and in gene cloning.
A vector should have the following features:
• Contain a replica that enables it to replicate in host cells.
• It should have several marker genes.
• It should have a unique cleavage site within one of the marker genes
so that insertion of foreign DNA into the marker gene leads to its
inactivation and identification of recombinant molecule.
• For the expression on cloned DNA, the vector DNA should contain
suitable control elements, such as promoters, terminators and
ribsome binding sites.

4. Vectors classification:
• The plant vectors are classified into:
1. Cloning vectors
2. Expression vectors
3. Integration vectors.

5. Cloning Vectors:
• Small piece of DNA into which a foreign DNA fragment is inserted for
cloning purposes.
• Characteristics of cloning vectors:
1. Ori(origin of replication) is a specific sequence of nucleotide from
where replication starts.
2. It should have selectable marker gene.
3. It should have restriction site:a synthetic multiple cloning site
(MCS) can be inserted into the vector.
4. Replicate inside the host cell to form multiple copies of the
recombination of DNA molecule
5. Less than 10kb in size

6. Types of cloning vectors:
• They allow the exogenous DNA to be inserted,stored, and manipulated mainly at
DNA level.
• Types
1. Plasmid vectors
2. Bacteriophage vectors
3. Cosmids
4. Phagemids
5. BACs and YAC
6. Shuttle vectors.

7. Plasmid vector :
• Plasmid vectors are double stranded, extra-chromosomal
DNA molecules, circular, self-replicating.
• Plasmid were the first vectors to be used in gene cloning.
• The size of Plasmid ranges from 1.0kb to 250kb.
• DNA insert of up to 10kb can be cloned in the Plasmid.
• The Plasmid have high Copy number which is useful for
production of greater yield of recombinant Plasmid for
subsequent experiments.
• Examples:pBR322, pUC18, F Plasmid, Col Plasmid.

9. Classification of plasmid:
• Fertility Plasmid:
Eg: F Plasmid of E.coli
• Col Plasmid:
Eg: ColE1 of E. Coli
• Resistance plasmid:
Eg:RP4 in pseudomonas
• Degradative plasmids:
Eg:TOL of F. PuPutida
• Virulence Plasmid:
Eg: Ti Plasmid of A.tumefacines

10. Based on origin:
• Natural plasmids: they occur naturally in prokaryotes.
Eg:ColEI
• Artificial Plasmid: They are constructed in vitro by reconvening
selected segments of two or more plasmids.
Eg:pBR322

11. pBR322:
• It is one of the first vectors to be
developed in 1977.
• The p indicates that if Plasmid, BR
indicates Bolivar and Rodriguez.
• 322 distinguish it from the other
plasmids produced in the same
laboratory e. g, pBR325, pBR327.
• It is 436bp in size less than 10 kb.

12. pUC18-Lac selection plasmid:
• It is 2750 bp in size and is one of the
most popular E. Coli cloning vectors.
• Derived from pBR322 in which only the
ori and the app genes remain.
• The restriction site are clustered into the
lac Z gene.

13. Advantages:
• Easy to manipulate and isolate because of small size.
• More stable because of circular configuration.
• Replicate independent of the host.
• High copy number.
Disadvantages:
• Large fragments cannot be cloned.
• Size range is only to 0 to 10kb.
• Standard methods of transformation are inefficient.

14. Bacteriophage vectors:
• Bacteriophage or pages are viruses which infect bacterial cells.
• The most common Bacteriophage utilised in gene cloning are Phage lambda
and M13 Phage.
• A maximum of 53 kb DNA can be packaged into the phage.
• If the vector DNA can be packaged into the phage.
• If the vector DNA is too small, it cannot be packaged properly into the phage.
• Example: phage Lambda, M13 Phage.

15. Phage Lambda:
• It is 49 kb in size and is used as a cloning vector.
• The genes related in term of function are
clustered together in the genome and allows the
genes to be switched on and off as a group rather
than individually.
• The linear double stranded DNA molecule has a
stretch of 12 nucleotides at its either ends which
acts as sticky ends or cohesive ends
• They can pair to form a circular DNA molecule
which is important for insertion into the bacterial
genome.

16. M13 phage vector:
• The M13 genome is 6.4 kb in length.
• Consists of ten closely packed genes for
replication of the phage.
• There is a single 507 nucleotide
intergeneric sequence into which new DNA
can be inserted.
• This region includes the ori gene.

17. Advantages:
• They are way more efficient than plasmids for cloning large inserts.
• Screening of phage plaques is much easier than identification of
recombinant bacterial colonies.

18. Cosmids:
• Cosmids are plasmids that incorporate the
Bacteriophage lambda DNA segment contains cohesive
terminal site.
• Cos sites are necessary for efficient packaging of DNA
into lambda phage particles.
• It is normally used to clone large DNA fragment of size
varyIng from 25 to 45 kb can be cloned.
• They are also packaged into phage capsids which
permits the foreign DNA fragment or genes to be
introduced into the host organism by the mechanism
of transduction.

19. Advantages:
• They have high transformation efficiency and are capable of
producing a large number of clones from a small quantity of DNA.
• Also they can carry up to 45kb of insert compared to 25kb carried by
plasmids and lambda.
Disadvantages:
• Cosmids cannot accept more than 50kb of the insert.

20. Bacterial Artificial chromosome:
• Bacterial artificial chromosomes are
similar to E. coli Plasmid vectors.
• They contain our and genes which encode
ori binding Proteins. These proteins are
critical for BAC replication.
• It is derived from naturally occurring F
Plasmid.
• The DNA insert size varies between 150 to
350 kb.

21. Advantages:
• They are capable of accommodating large sequence without any risk
of rearrangement.
• BACs are frequently used for studies of genetic or infectious
disorders.
• High yield of DNA clones is obtained.
Disadvantages:
• They are present in low copy number.
• The eukaryotic DNA inserts with repetitive sequences are
structurally unstable in BACs often resulting in deletion or
rearrangement.

22. Yeast Artificial chromosomes:
• A large DNA insert of up to 200kb can be closed.
• They are used for cloning inside eukaryotic cells.
These act as eukaryotic chromosome inside the host
eukaryotic cell.
• It possess the yeast telomere at each end.
• A yeast Centromere sequence is present which
allows proper segregation during meiosis.
• The ori is bacterial in origin.
• Both yeast and bacterial cells can be used as hosts.

23. Advantages:
• A large amount of DNA can be cloned.
• Physical maps of large genomes like the human genome can be
constructed.
Disadvantages:
• The overall transformation efficiency is low.
• The yield of cloned DNA is also low.

24. Shuttle vectors:
• Capable of replicating in two or more
types of hosts.
• Replicate autonomously or integrate
the host genome and replicate when
the host replicates.
• Commonly used for transporting
genes from one organism to another.

25. Expression vector:
• It allowing the exogenous DNA to be inserted stored and manipulated mainly at DNA level.
• Plant Expression vectors are mainly based on the Ti Plasmid of Agrobacterim tumefacines.
Plant virus are also used as expressive vectors.
• DNA vectors:
1. Cauliflower mosaic virus
2. Gemini virus
3. Mastrevirus
4. BegoBegomovirus.
• RNA virus
1. Tobacco mosaic viruses
2. Brome mosaic viruses
3. Hordeiviruses
4. Potexviruses
5. Comoviruses.

26. • Viruses are used in two ways:
1. Virus directly inserted into plant.
2. Virus indirectly inserted.

27. Ti Plasmid:
• The Ti Plasmid contains all the genes required
for tumor formation. Virulence genes are also
located on the To Plasmid. The vir genes
encode a set of proteins responsible for the
excision, transfer and integration of the T-DNA
into the plant nuclear genome.
• Ti Plasmid is grouped into two categories.
1. Nopaline type pTi
2. Octopine type pTi

28. Conclusion:
• Vector is a DNA molecule used a vehicle to artificially carry foreign
genetic material into another cell, where it can be replicated and
expressed.
Reference:
• https://cnx.org
• https://en.m.wikipedia.org
• https://cusb.ac.in