Genome Editing Based CRISPR System in Crop Improvement

The primary objective of sustainable agriculture is to rise food production in order to ensure global food security. However, various environmental factors impose limitations on crop yields, which threaten food sustainability across the world. The appearance of next-generation sequencing techniques and the generation of extensive genomic sequencing input for diverse crop plant species, alongside the progress of transcriptome, proteome, and metabolome data, have opened up opportunities to create new varieties of crop through genetic engineering. Advances in genome editing techniques revolutionized plant breeding through targeted alteration of different genes among diverse crop plant species. The bacterial derived Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 nuclease (Cas9), are among the most effective genome editing techniques that have been advanced in recent years. In addition to their universal application in all organisms tested thus far, CRISPR/Cas9 has also been praised for its simplicity, high efficiency, precision, versatility, and reproducibility. CRISPR/Cas9 has been used to achieve an extensive modifications, from subtle nucleotide changes as insertions/deletions within host genes, gene replacements and gene knock-ins by homologous recombination. Many agriculturally important and desirable traits result from random point mutations or indels at specific loci in either coding region of genes or respective promoters. Therefore, simulating these mutations in the genome of agricultural plants using gene editing methods can be a great progress in plant breeding. In this regard, the CRISPR/Cas platform has been used to target several genes implicated in phytopathogenic resistance, as well as abiotic stress and product quality. This chapter discusses the application of the CRISPR system in sustainable agriculture, along with challenges and future prospects.