CRISPR cas in agriculture and its applications in genome editing of plants new good or bad ?

Genome editing and crispr cas in agriculture

Genome editing refers to a technique for targeted alterations that modify, insert, replace, or delete DNA sequences from a genome.

What is genome editing?

Genome editing is a technique to precisely and efficiently modify DNA within a cell by adding, removing, or altering DNA in the genome. This involves ‘engineered nucleases’ which act as molecular scissors. Engineered nucleases include meganucleases, zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALENS), and CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) each has its own merits and limitations.

Categories of genome edited plants

categories of genome-edited plants they are SDN-1, SDN-2, and SDN-3. SDN stands for Site Directed Nuclease. The genome-edited plants derived from the use of genome editing techniques employing site-directed nucleases (SDNs) such ZFNs, TALENs, CRISPR, and other nucleases with similar functions are generally classified under three categories as

i) Site-Directed Nuclease (SDN)-1, site-directed mutagenesis without using a DNA sequence template;
ii) SDN-2, site-directed mutagenesis using a DNA sequence template; and
iii) SDN-3, site-directed insertion of gene/large DNA sequence using a DNA sequence template

Difference between sdn1 and sdn2 genome edited plants can be found here

CRISPR cas9

CRISPR Cas9 is the most common and efficient system of genome editing that involves the DNA targeting part (CRISPR) and the nuclease part (Cas9). The first component is a protein encoded by the Cas9 gene which cut the DNA molecule and the second component is an RNA originating from the CRISPR locus that contains the sequence specifying the DNA sequence to cut. Following the cut of the target DNA sequence, the CRISPR-Cas system takes advantage of naturally occurring cellular DNA repair mechanisms to delete genes, edit genes, or insert genes.

Applications of Genome Editing

Genome editing helps in target site gene mutation which is highly efficient. Genome editing has the below well-known applications:

1. It is highly efficient in making site-specific integration and gene stacking.
2. In the process of gene replacement via homologous recombination.
3. Utilized in chromosomal engineering through which site-directed deletions and translocations can be done.
4. Labeling and modifications of multiple genomic sites are possible through editing.
5. Transcription modulation of multiple genes and pathways.

CRISPR-cas in agriculture

CRISPR cas in agriculture field is a very novel field and one can say research in this area is still in its juvenile stage however with the advent of supreme court order allowing the use of genetically edited crops for use this field is set to recieve a lot of traction in the upcoming decades.

List of applications for Crispr cas in agriculture have been identified below :

1. CRISPR cas is used to create a high degree of genetic variability at a precise locus in the genome of crop plants.
2. A potential tool for multiplexed reverse and forward genetic study.
3. Precise transgene integration at specific loci.
4. Developing biotic and abiotic resistant traits in crop plants.
5. A potential tool for developing virus-resistant crop varieties.
6. crispr cas can be used to eradicate unwanted species like herbicide-resistant weeds and insect pests.
7. A potential tool for improving polyploid crops like potato and Wheat.

About GEAC

The GEAC is responsible for appraisal of proposals relating to release of genetically engineered (GE) organisms and products into the environment including experimental field trials. Official website of GEAC can be found here. In india currently genetically modified crops only GM cotton has been allowed to this date. However with advent of crispr cas in agriculture new more advanced genetically modified crops are expected especially the GM Mustard crop.