Production of Virus-Resistant Plants Through CRISPR-Cas Technology

Abstract

Clustered regularly interspaced short palindromic repeats (CRISPR) are widely found in bacterial and archaeal genomes as a defence mechanism against invading viruses and plasmids. The CRISPR locus consists of segments of prokaryotic DNA with short repetitions of base sequences. Each repetition is followed by short segments of ‘spacer DNA’ from earlier exposed bacterial virus or plasmid. CRISPR spacers recognize and cut these exogenous genetic elements in a manner analogous to RNA interference in eukaryotic organisms. The CRISPR interference technique has enormous potential application, including altering the germline of humans, animals, other organisms and plants. The organism’s genome can be cut at any desired location by delivering the Cas9 protein and guide RNAs into a cell. Thus CRISPR-Cas system represents a powerful tool in developing resistance to DNA and RNA plant viruses by editing and inserting novel traits precisely at chosen loci into plants and offers enormous potential in classical breeding. It has opened new way to get virus-resistant plants either by directly targeting and cutting the viral genome, or by modifying the host genome itself to introduce viral immunity. In this chapter, recent progress demonstrating the efficacy of the CRISPR/Cas technology against DNA and RNA plant viruses is discussed.