Adoption of CRISPR-Cas for crop production: present status and future prospects

Abstract

Background: Global food systems in recent years have been impacted by some harsh environmental challenges and excessive anthropogenic activities. The increasing levels of both biotic and abiotic stressors have led to a decline in food production, safety, and quality. This has also contributed to a low crop production rate and difficulty in meeting the requirements of the ever-growing population. Several biotic stresses have developed above natural resistance in crops coupled with alarming contamination rates. In particular, the multiple antibiotic resistance in bacteria and some other plant pathogens has been a hot topic over recent years since the food system is often exposed to contamination at each of the farm-to-fork stages. Therefore, a system that prioritizes the safety, quality, and availability of foods is needed to meet the health and dietary preferences of everyone at every time.

Methods: This review collected scattered information on food systems and proposes methods for plant disease management. Multiple databases were searched for relevant specialized literature in the field. Particular attention was placed on the genetic methods with special interest in the potentials of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and Cas (CRISPR associated) proteins technology in food systems and security.

Results: The review reveals the approaches that have been developed to salvage the problem of food insecurity in an attempt to achieve sustainable agriculture. On crop plants, some systems tend towards either enhancing the systemic resistance or engineering resistant varieties against known pathogens. The CRISPR-Cas technology has become a popular tool for engineering desired genes in living organisms. This review discusses its impact and why it should be considered in the sustainable management, availability, and quality of food systems. Some important roles of CRISPR-Cas have been established concerning conventional and earlier genome editing methods for simultaneous modification of different agronomic traits in crops.

Conclusion: Despite the controversies over the safety of the CRISPR-Cas system, its importance has been evident in the engineering of disease- and drought-resistant crop varieties, the improvement of crop yield, and enhancement of food quality.

Keywords: CRISPR-Cas9; Environmental stressors; Food security; Genetic engineering; Genome editing.

Figure 1. Workflow for the use of CRISPR-Cas9-based gene editing in plants.

(A) Selection of the target gene for plant transformation and designing of single-guide RNA (sgRNA) for the target gene. (B) construction of suitable vector, (C) genetic transformation for the delivery of CRISPR/Cas9 via suitable bacteria delivery system like the Agrobacterium mediated transformation method/ribonucleoprotein (RNP), (D) tissue culture for callus induction, (E) plant regeneration from CRISPR/Cas9-mutated tissues, (F) generation of T₀ CRISPR/Cas9-mutated transgenic plants, (G) screening of transgenic plants to detect on- and off-target efficiency of CRIPR-Cas9,by detection of on- and off-target efficiency by Sanger sequencing, (H) self-pollination of T₀ transgenic plants for generation of homozygous T₁ plants, (I) generation of CRISPR/Cas9-mutated T₀ Seeds, (J) generation of transgene-free T₁ progeny, (K) phenotypic analysis of T1 plants and other analysis.