Performance and transcriptomic analysis of sorghum bicolor responding to drought stress

Drought is a severe causal factor of reduced crop yields than other abiotic stresses. Therefore, four sorghum genotypes underwent evaluation for their drought tolerance under three irrigation levels (100%, 70%, and 40% from evapotranspiration) under three sowing dates at the Higher Institute for Agricultural Cooperation Farm, Regwa region, Alexandria Desert Road, Egypt, to study the mean performance of grain yield plant-1 and transcriptomic analysis. The performance results reported that Shandaweel-6 and Hybrid-306 revealed the highest drought-tolerant hybrids, while Dorado and Giza -113 cultivars showed the lowest. The transcriptomic profiling of sorghum under normal and drought stress used the RNA-Seq method. Two differentially-expressed genes (DEGs) in leaves respond to drought. In the DREB2 case, the greatest average fold change showed 10.7 and 9.3 for the tolerant hybrids, Hybrid-306 and Shandaweel-6, respectively. Both genotypes performed significantly higher than the average fold change calculated for the sensitive genotypes Dorado and Giza-113 cultivars. This study contributes to a better understanding of the molecular basis of drought tolerance of sorghum and promotes sorghum improvement.