Africa must advance rapidly to meet growing food demands and raise incomes while protecting the environment for future generations. Crop improvement through genome editing will provide this opportunity.
Genome editing of crops represents the latest scientific progress with potential aimed at fighting the persistent food crisis situations in developing societies. Genome editing is simply inserting, deleting or replacing DNA at a specific site in the genome of a cell or organism and this can be achieved in the laboratory using engineered nucleases known as Molecular Scissors.
A strand of DNA is cut at a specific point and naturally existing cellular repair mechanisms then fix the broken DNA strands and the way they are repaired affects gene function. The families of engineered nucleases used are Zinc Finger Nucleases (ZFNs), Meganucleases, Transcription Activator-Like Effector-based Nucleases (TALEN), and the Clustered Regularly Interspaced Palindromic Repeats (CRISPR).
The emergence of CRISPR Associated System (CRISPR-Cas9) has revolutionized the field of genome editing and is now the most commonly used genome editing tool. Genome editing with CRISPR-Cas9 has been demonstrated in some crops like rice, lettuce, maize, potato, soybean and some other leguminous crops. In China, CRISPR has been used to produce a variety of wheat resistant to powdery mildew disease and presently in Japan; field trials for high yield gene edited rice are ongoing.
Genome editing/CRISPR-Cas9 system has potential for crop improvement in Africa because this technology is easier, faster and cheaper than genetic engineering or conventional breeding. It also offers new opportunities for developing improved crop varieties with clear-cut addition of valuable traits and removal of undesirable traits. Crops of reliable high yields, resistance to diseases, pests, and stress factors can now be readily available.
Genome editing can be used for improvement of some of our staple crops in Africa like cassava, cowpea, yam, pearl millet, sweet potato, sorghum etc. Cassava brown streak virus affects cassava production greatly and CRISPR could offer a solution.
CRISPR-Cas9 system can be applied in the improvement of cowpea for resistance to abiotic stress. Abiotic stresses affecting cowpea production include drought, heat, and low soil fertility. Although the crop is known to be drought tolerant, its yield can be reduced significantly when exposed to seedling, mid-season or terminal drought. Genome editing can be used to improve the nutritional quality of these staple crops and also applied to local crop varieties that smallholder farmers in Africa prefer, to improve their livelihood.
Despite the debates on the acceptance of Genetically Modified Crops; there is hope for better policies and regulations concerning genome/CRISPR edited crops as it possible to edit the genome of crops without adding any foreign DNA. Genome editing holds great promise for crop improvement in Africa and can be explored to tackle food insecurity and increase agricultural productivity. Africa must rise to its responsibility and take advantage of this opportunity in the global fight for zero hunger.