Sorghum as a Model Crop for Drought Stress Tolerance

Sorghum is one of the most significant C4 cereal crops grown in dry and semi-arid regions of the world. It is a major staple crop for millions of people in Sub-Saharan Africa and South Asia. Drought is an important constraint on agricultural production and productivity around the world. It has a significant impact on plant growth, development, and yields. Drought stress risks food security by having a substantial impact on sorghum growth and development, grain yields, and nutritional quality. Sorghum has become known as a drought-tolerant model crop when compared with many other crops. Its ability to withstand extreme environmental conditions makes it a feasible model crop for studying abiotic stress responses and developing stress-tolerant crops. Sorghum response and/or tolerance mechanisms include morphological, physiological, and molecular changes. Drought stress tolerance mechanisms in sorghum include drought escape, early flowering, stay-green, drought avoidance, leaf area, osmotic adjustment, stomata-mediated drought responses, cuticular wax production, root characteristics, and drought tolerance. Biotechnology and its advanced approaches, such as QTL, marker-assisted backcrossing, genetic engineering, and others, are used for screening drought-tolerant genotypes that can withstand drought stress. Therefore, focusing on the drought-tolerant genotypes will boost the speed of the sorghum breeding program, which will feed millions of people worldwide, particularly in Sub-Saharan Africa.