CRISPR/Cas9 and its derivatives to improve crop biotic stress resistance: Current status and prospects

Various pathogens, pests, and parasites exert biotic stress on plants, responsible for more than 25–30 % of crop losses worldwide. To address growing population pressures and assure global food security, disease-resistant crops of high quality and yield must be developed. Traditional breeding approaches have moderate success against biotic stress tolerance traits. Hence, a more advanced transgenic approach is required to produce stress-tolerant crops. In the last two decades, significant advances in genome editing technology using meganuclease, zinc figure nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) for improving crop attributes like yield enhancement, quality improvement, and resistance to biotic stressors have been developed. We closely analyzed the adequate genome editing studies to provide host plants with resistance against various biotic agents, such as viruses, fungi, oomycetes, bacteria, nematodes, insect pests, and parasitic weeds. This review summarized the most recent CRISPR/Cas9 and its derivatives mediated gene editing strategies to enhance biotic stress in plants. In addition, we discuss the difficulties and opportunities that will need to be fully utilized in genome-editing technology for crop biotic stress improvement in the future. • CRISPR/Cas9 technology and its derivatives have emerged as a boon for plant genome editing. • CRISPR/Cas9 has been utilized to target host susceptible genes which enhances resistance against biotic stresses.