CRISPR/Cas system-mediated gene editing for disease resistance in food crops: current status and future directions

The global population is expected to reach 9.7 billion by 2050, which will put pressure on food production systems that are already vulnerable to climate change. Crop diseases caused by pathogenic bacteria, fungi, and viruses cause significant yield losses in major food crops. Conventional breeding has contributed to developing resistant cultivars, but it is time-consuming and limited by genetic variability. The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) systems have emerged as transformative tools for the precise and rapid improvement of disease resistance in food crops. This review presents a comprehensive overview of the application of CRISPR/Cas-based genome editing platforms such as Cas nucleases, base editors, and prime editor systems for developing disease resistance in food crops. These technologies enable targeted knockout of susceptibility (S) genes, precise nucleotide substitutions, promoter engineering, and direct viral RNA interference for imparting disease resistance. Delivery of DNA-free ribonucleoprotein (RNP) complexes further supports the development of non-transgenic (GM-free) crops for quick regulatory approvals and field cultivation. The review highlights successful applications of CRISPR/Cas tools across major cereals, legumes, and tuber crops for developing disease resistance. Additionally, CRISPR-enabled diagnostics provide new prospects for rapid pathogen detection in field conditions. It also draws in roads for future adoption of CRISPR/Cas tools for developing disease resistance in major crops and extension to minor cereals such as millets. Prudent applications of CRISPR/Cas tools will play a pivotal role in promoting sustainable agriculture and achieving the United Nations Sustainable Development Goal of Zero Hunger.