Transcript
HARMONAL MUTAGENESISCREATED BY : CHAVAN MAHADEV RAJARAM
COLLEGE OF AGRICULTURE , DAPOLIM.SC (AGRI)
Department of Agricultural Botany(GPB)
Mutagenesis
It is a process by which the genetic information of an organism is changed in a stable manner, resulting in a mutation.
It may occur spontaneously in nature, or as a result of exposure to mutagens.
It can also be achieved experimentally using laboratory procedures
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DNA may be modified, either naturally or artificially, by a number of physical, chemical and biological agents, resulting in mutations In 1927, Hermann Muller first demonstrated that mutation with observable changes in the chromosomes can be caused by irradiating fruit flies with X-ray.
HISTORY :
Lewis Stadler also showed the mutational effect of X-ray on barley in 1928, and ultraviolet (UV) radiation on maize in 1936.
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Types of mutagenesis1. Directed mutagenesis
Directed mutagenesis can be done using : Directed mutagenesis may define is a change in the nucleic acid sequence (or genetic material) of an organism at a specific predetermine Site. directed mutagenesis is incorporation of a desired amino acid (of one's choice) in place of a specific amino acid in a protein or a polypeptide.Site-directed mutagenesis is the technique for generating amino acid coding changes in the DNA (gene). By this approach specific (site-directed) change (mutagenesis) can be made in the base (or bases) of the gene to produce a desired enzyme.
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2. Site-directed mutagenesis• In molecular biology and genetics, mutations are changes in a genomic sequence.• Mutations are caused by radiation, viruses, transposes and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.• Site-directed mutagenesis, also called site-specific mutagenesis or oligonucleotide directed mutagenesis, is a molecular biology technique often used in bio molecular engineering in which a mutation is created at a defined site in a DNA molecule.
3. PCR mutagenesis
4. Insertional mutagenesis
5. Signature tagged mutagenesis
6. Transposon mutagenesis
Role of plant Harmon in mutagenesis
The experiments are designed to measure the effects of
- Abscisic acid (ABA) - Auxin
Samples are - Wild-types
- mutated at rop genes
Maize rop mutants
There are nine rop genes in maize
used samples with mutation of the rop 2, rop 6 and rop 7 genes.
How do you get the mutation?
Experiment set up
Germinate seedlings in a water soaked paper towel
Measure root length before treatment
Add auxin or ABA Measure after 24 and 48hrs Average the length
Auxin – rop 6/7
Day Two Comparison
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Mutant grow th
Day One Comparison
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Mutant grow th
Mutant Effect !!rop 6/7 Double mutantSLOWER root growth
Auxin rop 2Day One Compaison
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Day Two comparison
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Wildtype growth
Mutant growth
No Mutant Effect !!!rop 2 mutantSAME as wild-type
ABA rop 2 Day One Comparison
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Day Two Comparison
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Wildtype grow th
Mutant grow th
Mutant Effect !!rop 2 mutantSLOWER root growth
ABA- rop 6/7Day One Comparison
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Mutant grow th
Day Two Comparison
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Wild-type grow th
Mutant grow th
No Mutant Effect !!!rop 6/7 mutantSAME as wild-type
Summary of Results ABA, Auxin
Auxin rop 6/7 Supports hypothesis Auxin rop 2 No effect
ABA rop 2 Supports hypothesis
ABA rop 6/7 No effect
Root growth
Rop
Hormonal Factors of Mutagenesis and Anti-Mutagenesis Regulation.
Case study 1
Mekhtizadeh Emin RZA292 92
The genetic activity of phytohormones (Phs) was studied. The investigation was conducted with 4 plants (Allium fistulosum, Lycopersicon esculentum, Triticum aestivum, and Gossypium hirsutum). The action of Phs on plant genetic processes was evaluated by chromosome aberration testing. It was observed that the exogenic Phs exerted a stabilizing effect on spontaneous plant mutagenesis. The use of Phs before and after the action of mutagenic factors contributed to an increase in the anti-mutational or reparative function of the plants´ genes. It was observed that the Phs exhibited gene protective or reparative activity. The absence of clearly expressed dependence of these effects on Ph dose was recorded.
Turkish Journal of Biology 2009 Vol. 33 No. 1 pp. 15-20Conclusion :
Beale, G. (1993). "The Discovery of Mustard Gas Mutagenesis by Auerbach and Robson in 1941". Genetics 134 (2): 393–399.Crow, J. F.; Abrahamson, S. (1997). "Seventy Years Ago: Mutation Becomes Experimental". Genetics 147 (4): 1491–1496https://en.wikipedia.org/wiki/Mutagenesishttp://www.cabdirect.org/search.htmdergipark.ulakbim.gov.tr/tbtkbiology/article/view
Reference :
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