علم تربية النبات يبحث في تحسين الصفات الوراثية للنباتات التي لها قيم إقتصادية بالنسبة للإنسان .التربية و البيوتكنولوجي
تنقسم تربية النبات في نشاطين:
التعديل الجيني
تقييم النبات يؤدي التحكم في عملية التلقيح إلى ظهور أصناف خلطية جديدة تعطي محصول بشكل أفضل تقنيات زراعة الأنسجة لها تأثير كبير في التعامل مع التنوع الجيني حيث تم بالفعل تعديل أكثر من 50 نوع مختلف وراثيا إما بطرق تعتمد على ناقلات Agrobacterium أو ناقلات Liposome – microinjection – Biolistic حيث لعبت تقنيات زراعة الأنسجة دورا رئيسيا في تطوير الهندسة الوراثية النباتية، و خاصة نقل الجينات بكفاءة و إستعادة النباتات المحورة وراثيا
التكنولوجيا الحيوية النباتية: و يتم فيها التعديل الوراثي للخلية النباتية عن طريق إدخال جزء معين من الحمض النووي (الصفة المرغوبة) من مصدر مختلف وراثيا
11. للنبات التقليدية التربية
الجيني بالنقل التربية
Using plant
biotechnology, a single
gene may be added to
the strand.
Desired gene Commercial variety New variety
(transfers)
=
Desired gene
(only desired gene is followed)
30. The genetic changes include:
• Chromosomal breakage
• Deletion
• Translocations
• Gene amplification
• Several mutations
31. Somaclonal variation in wheat. The parent plants are at the right and left.
Between the parents are plants regenerated from tissue cultures that vary in
height and presence of awns
32. Protoplasts
• Somatic hybridization or protoplast fusion is a promising method to
overcome different problems encountered with sexual reproduction
Somatic cell hybridization
33. PLANT GENETIC ENGINEERING
Plant genetic engineering refers to the transfer
of a foreign DNA segment, which codes for
specific genetic information, from a donor plant
species into a recipient species by means of a
bacterial plasmid, virus, or other vector
34. INTRODUCTION
• Gene transfer is to transfer a gene from one DNA
molecule to another DNA molecule.
• The directed desirable gene transfer from one organism
to another and the subsequent stable integration &
expression of foreign gene into the genome is referred as
genetic transformation.
• Transient transformation occur when DNA is not
integreted into host genome
35. Introduction of the vector containing the foreign
DNA segment into cells of host plants,
Integration of the foreign DNA into the genome
of the host cell
Expression of the foreign DNA in the phenotype
of the crop plant
36. • Stable transformation occur when DNA is integrated
into host genome and is inherited in subsequent
generations.
• The transferred gene is known as transgene and the
organism that develop after a successful gene transfer is
known as transgenic.
38. METHODS OF GENE TRANSFER
DNA transfer by natural
methods
• 1. Conjugation
• 2. Bacterial transformation
• 3. Retroviral transduction
• 4. Agrobacterium mediated
transfer
39. DNA TRANSFER BY ARTIFICIAL METHODS
• Physical methods
• 1. Microinjection
• 2. Biolistics transformation
• Chemical methods
• 1. DNA transfer by calcium phosphate method
• 2. Liposome mediated transfer
• Electrical methods
• 1. Electroporation
43. • The T-DNA region of any Ti
plasmid is defined by the
presence of the right and the
left border sequences.
• These border sequences are
24 bp imperfect repeats.
• Any DNA between the
borders will be transferred
in to the genome of the
plant.
44. Ti-Plasmid mediated
transfer of gene into a plant
• The Ti-Plasmid has an innate ability to transmit bacterial
DNA into plant cells.
• The gene of a donor organism can be introduced into the
Ti plasmid at the T-DNA region
• This plasmid now becomes a recombinant plasmid.
• By Agrobacterium infection, the donor genes can
transferred from the recombinant Ti- Plasmid and
integrated into the genotype of the host plant.
45. The target gene in the small T-DNA plasmid
in E. coli, isolate the plasmid and use it to
transform A. tumefaciens containing the
disarmed Ti plasmid
46. VECTORLESS or DIRECT GENE
TRANSFER
Physical methods
1. Biolistics transformation
2. Microinjection
Chemical methods
1. DNA transfer by calcium phosphate method
2. Liposome mediated transfer
3. Transfer of DNA by use of polyethene glycol
Electrical methods
1. Electroporation
47. Biolistics or Microprojectiles
• Biolistics or particle bombardment is a physical
method that uses accelerated microprojectiles to
deliver DNA or other molecules into intact tissues
and cells.
• The gene gun is a device that literally fires DNA into
target cells .
• The DNA to be transformed into the cells is coated
onto microscopic beads made of either gold or
tungsten.
48. • The coated beads are then attached to the end of the
plastic bullet and loaded into the firing chamber of
the gene gun.
• An explosive force fires the bullet with DNA coated
beads towards the target cells that lie just beyond the
end of the barrel.
• Some of the beads pass through the cell wall into the
cytoplasm of the target cells
50. Electroporation
• Electroporation uses electrical pulse to produce
transient pores in the plasma membrane thereby
allowing DNA into the cells.
• These pores are known as electropores.
•
51. • The cells are placed in a solution containing DNA and
subjected to electrical pulse to cause holes in the
membrane.
• The foreign DNA fragments enter through holes into
the cytoplasm and then to nucleus.
52. Advantages of Electroporation
• 1. Method is fast.
• 2. Less costly.
• 3. Applied for a number of cell
types.
• 4. Simultaneously a large
number of cell can be treated.
• 5. High percentage of stable
transformants can be produced
53. Microinjection
• The microinjection is the process of transferring the
desirable DNA into the living cell ,through the use of
glass micropipette .
• Glass micropipette is usually of 0.5 to 5 micrometer,
• easily penetrates into the cell membrane and nuclear
envelope.
• The desired gene is then injected into the sub cellular
compartment and needle is removed
56. SCREENING OF TRANSGENE
• The presence of transgene or gene of interest is
detected by several methods:
• A selectable marker gene
• Southern blot techniques
• Northern bolt technique
• Western blot technique
57. Comparing Genetic Modification Techniques
Whole organism Molecule Molecule
Thousands of genes Unknown Single gene
Genetic change poorly
characterized
Genetic change poorly
characterized
Gene function
well understood
Between species
and genera
Not applicable No limitations
Selective Breeding Mutation breeding Transgenic breeding
Level
Precision
Certainty
Limits