Abiotic Stress Tolerance in Cereals Through Genome Editing

Improving crop yield and developing new crop varieties are the top priorities in the twenty-first century due to its important agricultural and socioeconomic values. Recent revolutions in genome editing have paved the way to improve the desirable characteristics in various crops by targeting the related genes precisely. Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) technology is a newly emerged, highly effective, and robust site-specific genome editing tool used for precise mutagenesis induction in various crop species. From comparison of this technology with two other currently used sequence-specific nuclease genome editing tools: transcription activator-like effector nucleases (TALENs) and zinc finger nucleases (ZFNs), we summarize that CRISPR-Cas technology has more potential to edit genomes efficiently. The availability of genome sequences for numerous crops, along with rapid advancements in genome editing techniques, has created opportunities to breed for almost any given desirable trait. CRISPR-Cas technology has recently been widely used to study the functions of several genes in different cereals including rice, wheat, and maize and to determine their potential in quality improvement. Designing of most efficient and accurate tools of CRIPSR has motivated and enabled researchers to modify cereal genes for improved traits. In addition to summarizing various experimental applications and successfully edited genes in cereals by single and multiplex gene editing systems of CRISPR-Cas technology for enhancing abiotic stress tolerance, we also highlight the diversity of proteins and mechanisms in these systems. We also consider future challenges and potential directions for research developments in the era of CRISPR-Cas technology.