CRISPR/Cas tool designs for multiplex genome editing and its applications in developing biotic and abiotic stress-resistant crop plants

Abstract

Plants are prone to several biotic and abiotic stresses, reducing crop yields. The crop yield reductions due to these stresses need addressing to maintain an adequate balance between the increasing world population and food production to avoid food scarcities in the future. It is impossible to increase the area under food crops proportionately to meet the rising food demand. In such an adverse scenario overcoming the biotic and abiotic stresses through biotechnological interventions may serve as a boon to help meet the globe's food requirements. Under the current genomic era, the wide availability of genomic resources and genome editing technologies such as Transcription Activator-Like Effector Nucleases (TALENs), Zinc Finger Nucleases (ZFNs), and Clustered-Regularly Interspaced Palindromic Repeats/CRISPR-associated proteins (CRISPR/Cas) has widened the scope of overcoming these stresses for several food crops. These techniques have made gene editing more manageable and accessible with changes at the embryo level by adding or deleting DNA sequences of the target gene(s) from the genome. The CRISPR construct consists of a single guide RNA having complementarity with the nucleotide fragments of the target gene sequence, accompanied by a protospacer adjacent motif. The target sequence in the organism's genome is then cleaved by the Cas9 endonuclease for obtaining a desired trait of interest. The current review describes the components, mechanisms, and types of CRISPR/Cas techniques and how this technology has helped to functionally characterize genes associated with various biotic and abiotic stresses in a target organism. This review also summarizes the application of CRISPR/Cas technology targeting these stress in crops through knocking down/out of associated genes.

The Potential of CRISPR/Cas Technology to Enhance Crop Performance on Adverse Soil Conditions

“…Following the success of CRISPR/Cas technologies in single gene editing, several modifications were developed to enhance and diversify their use [39,59]. The multiplex CRISPR approach is a strategy that enables the editing of multiple genes in a single transformation event and uses multiple gRNAs delivered at once to achieve this goal [60][61][62][63]. Abdallah et al [60] used three distinct gRNAs to knockout five TaSal1 genes in wheat, resulting in drought-tolerant seedlings.…”

Plant virus resistance biotechnological approaches: From genes to the CRISPR/Cas gene editing system

“…Because eukaryotic viruses have not yet evolved the ability to withstand CRISPR immune systems, this method has an advantage. The CRISPR/Cas9 system's ability to target and cleave just dsDNA, however, means that it can only be used to combat DNA viruses (Singh et al, 2022).…”