Different strategies were identified in response to drought among the four genotypes and the two Sorghum race allowing to state the tolerance of durra race compared to the caudatum one and, within the durra race, the drought tolerance of the genotype IS22330. It retained high biomass production and high tolerance index, it had a low threshold of fraction of transpirable soil water and high capacity to recover leaf apparatus after drought stress. Furthermore in this study, the expression levels of four genes highlighted that they could be used as proxy for drought tolerance. Dehdrine (DHN) could be used for screening drought tolerance both in durra and in caudatum races. NADP-Malic Enzyme, Carbonic Anhydrase (CA) and Plasma membrane Intrinsic Protein (PIP2-5), being up-regulated by drought stress only in durra race, have a more limited, though nonetheless useful application. In the tolerant durra genotype IS22330 in particular, the regulation of stomatal openings was strongly related to NADP-Malic Enzyme expression.