Updates and Applications of CRISPR/Cas Technology in Plants.

The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) genome editing technology, derived from the adaptive immune system of bacteria, has now been recognized as one of the most useful genetic tools in genome engineering. Short stretch of RNA guides the Cas enzyme to precise locations within the target genome of living organisms to accurately modify and control the functions of genes with high accuracy. Cas-mediated genome editing is scalable, practically feasible, and permits the research community to expound the functional organization of the hereditary material and helps to understand the relationship between genetic variations and biological phenotypes. Although CRISPR/Cas system has opened many possibilities in the field of genetic engineering, it still has some shortcomings, such as constraints of the protospacer-adjacent motif (PAM) sequence, relatively larger size of the Cas9 gene and higher chances of off-targeting. To overcome these shortcomings, many new Cas9 variants have been engineered with improved features such as specificity and editing efficacy. Anticipated traits can be developed in plants with high utility in agriculture. For the past decade, this editing system has made significant progress and has been widely used in genome editing to create gene knock-ins and knock-outs. Genome editing is mediated either by non-homologous end joining (NHEJ) or homology-directed repair (HDR) mechanism, consequently resulting in desired mutations that directly enhance plant performance. This paper summarizes the new variants of the CRISPR/Cas system and applications of the CRISPR system in plant science for the enhancement of various attributes such as yield, quality, nutritional factors, stress tolerance, and herbicide tolerance through knock-in and knock-out strategies. [ABSTRACT FROM AUTHOR]