The soluble sugars may directly influence inulin concentration in tuber of Jerusalem artichoke. Sucrose, fructose and glucose have been reported as the main parameters influencing the regulation of the activities of inulin-metabolizing enzymes (Vandoorneet al., 2012; De Roover et al., 2000). Since inulin content was increased under mild water stress this indicates that sucrose trans-port from source leaves to sink roots was not inhibited under water stress (Vandoorne et al., 2012). Valluru and Van den Ende (2008)reported that increases in inulin accumulation could protect cells from dehydration during water stress. Also, plants have the capac-ity to synthesize secondary metabolites such as sugar, inulin and fructans, all known as osmolytes that allow this plant to performosmotic adjustment (Delatorre-Herrera et al., 2010). The result srevealed that increasing the osmotic adjustment such as inulin constituting factors of drought resistance in Jerusalem artichoke.There fore, it could be hypothesized that Jerusalem artichoke genotypes with high inulin content might exhibit improved resistance to water deficit.