The CRISPR Revolution In Crop Improvement

New technologies for enhancing crop productivity and improving crop quality have always been eagerly pursued by scientists worldwide.

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With time, technologies have emerged and evolved, and we now stand at the gates of an era of precision genome engineering of crop plants. The newest addition to the genome engineering toolkit is the precise editing of a specific gene by either removing or adding small bits of DNA to it, more easily than any of its predecessor techniques. This new addition to the group of genetic engineering techniques is popularly called CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated nuclease9).

CRISPR/Cas9 system

The CRISPR/Cas9 is an adaptive immune system of bacterial cells against other foreign entities like bacteriophages and foreign plasmids. In structure, CRISPR loci are short repeat sequences separated by spacer sequences. These spacer sequences are remnants of genetic sequence of pathogens that attacked the bacterial cell in the past, and act as a sort of a library to recognise any future attack by the same pathogen. If the same pathogen attacks the cell, the spacer sequences are used as a genetic memory to detect the invaders and activate Cas9 to degrade the intruder's DNA. The CRISPR/Cas9 system was explored by many researchers, and then in 2012, two scientists, Jennifer A. Doudna, and Emmanuelle Charpentier, demonstrated the adaptability of this system to cut any desired DNA sequence. At present CRISPR/Cas9 system is being used to edit specific genomic regions of a number of organisms, including plants, animals and viruses.