Genome Editing for Crop Biofortification

Fluctuations in global climatic conditions as well as biotic and abiotic stresses circumscribe agricultural productivity and exacerbate the challenges associated with the increasing demands for food supply worldwide. Plant breeding practices have enabled the generation of hybrid plant varieties with augmented nutritional value and increased productivity. Nevertheless, obtaining novel varieties from existing gene pools is challenging for plant breeders, and in this light, genetic engineering technology promotes genetic diversity by introducing new genes into crops. However, transgene technology that involves random insertion of foreign DNA into the nuclear genome of the plant leads to positional effects and in some cases, transgene silencing. In this context, genome editing technologies have proved to be powerful tools that enable precise modification of specific target sites within the crop genome, thus dispensing with the presence of foreign DNA in these genome-edited plants. The highly targeted CRISPR-based genome editing technology dispenses with the ethical issues associated with transgenic crops. This tool has been widely used in crop biofortification programs due to its facile design, high efficacy, excellent reproducibility, low cost, and quick cycle. Several commercially important crops such as wheat, rice, maize, barley, tomato, and potato have been biofortified using CRISPR technology. In particular, this technology has been successful in enhancing crop quality by imparting aroma, sweetness, and increased shelf life in addition to quantitative augmentation of proteins, starch, oleic acid, gamma-aminobutyric acid (GABA), anthocyanin, and a host of other important crop qualities. Also, anti-nutrients such as glutens and phytic acid have been downregulated using CRISPR-based genetic engineering. Such biofortified crop varieties would enable the creation of "high nutrition" farms that would ensure global food security by addressing global malnutrition and hunger. Also, it would help in formulating a gene repository for generating high-value food for the twenty-first century. Thus, genome editing has proved to be a remarkable methodology that has revolutionized crop breeding in recent times. The current review addresses the importance of biofortification in ensuring food security as well as biofortification of crops using genome editing to impart nutraceutical attributes and diminish anti-nutrient contents. Additionally, regulatory issues associated with the use of this technology are addressed. Crop biofortification strategies toward future sustainable development programs are also discussed.