Biotechnological tools

MEL -453

1. Biotechnological approaches in plant disease management

2. Biotechnology It is defined as the manipulation , genetic modification and multiplication of living organisms through novel technologies such as tissue culture and genetic engineering resulting in the production of improved or new organisms and product that can be used in variety of ways

3. Major biotechnological tools Selection and breeding Genetic analysis Tissue culture Genetic engineering DNA Analysis

4. Selection and breeding It can include manipulating microbes, plants or animals and choosing desirable individuals or populations as breeding stock for new generation

5. Genetic analysis It is the overall process of studying and researching in field of science that involve genetics and molecular biology (i.e.) looking at chromosome, DNA pattern, and DNA sequences.

6. Tissue culture It is the in vitro cultivation of plant cells, tissues, organs, embryos, seeds and protoplast on nutrient media under controlled or aseptic conditions in a laboratory.

7. Genetic engineering can be defined as changing of genes by using i n vitro process(gene cloning + rDNA technology).

8. DNA Analysis T his occurs through two methods 1. PCR 2. RFLP Mapping PCR (Polymerase chain reaction) makes copies of DNA segment RFLP mapping (Restricted Fragment Length Polymorphism) detects patterns in DNA that can indicate the presence of a gene for a trait

9. Enzymes used in biotechnology Genetic engineering is a tool to develop the plants having gene of interest. The enzyme used are Restriction endonuclease DNA ligase Methylase DNA Polymerase

10. Restriction endonuclease A  restriction enzyme  is an enzyme that cuts DNA after recognizing a specific sequence of DNA. Restriction enzymes are called as molecular scissors. Scientists can use restriction enzymes to cut a single gene from a larger piece of DNA. Restriction enzymes evolved in bacteria. Properties They break phosphodiester bond that link adjacent nucleotides in DNA molecule.

11. Methylase   Methyltransferase or methylase catalyzes the transfer of methyl group (-CH 3 ) to its substrate. The process of transfer of methyl group to its substrate is called methylation . •  Methylation is a common phenomenon in DNA and protein structure.

12. Methylation normally occurs on cytosine (C) residue in DNA sequence. In protein, methylation occurs on nitrogen atom. •  DNA methylation regulates gene or silence gene without changing DNA sequences, as a part of epigenetic regulation. •  In bacterial system, methylation plays a major role in preventing their genome from degradation by restriction enzymes . It is a part of restriction – modification system in bacteria.

13. DNA polymerase DNA polymerase  (DNAP) is a type of enzyme that is responsible for forming new copies of DNA , in the form of nucleic acid molecules. Nucleic acids are polymers, which are large molecules made up of smaller, repeating units that are chemically connected to one another. DNA polymerase is responsible for the process of DNA replication, during which a double-stranded DNA molecule is copied into two identical DNA molecules.  It is used to copy DNA molecules in test tube via polymerase chain reaction(PCR)

14. Plasmids A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. When a bacterium divides, all of the plasmids contained within the cell are copied such that each daughter cell receives a copy of each plasmid. Bacteria can also transfer plasmids to one another through a process called conjugation.

15. Gel electrophoresis It is a method for separation and analysis of macromolecules ( DNA ,  RNA  and  proteins ) and their fragments, based on their size and charge . It is used in clinical chemistry to separate proteins by charge and/or size and in  biochemistry  and  molecular biology  to separate a mixed population of DNA and RNA fragments by length, to estimate the size of DNA and RNA fragments or to separate proteins by charge.