For the first time, the effect of pre-treatment of seeds with metabolically active substances on the accumulation of biomass by soft wheat seedlings in conditions of water deficiency, modeled with PEG 6000. It was found that metabolically active substances enhance the accumulation of biomass water intake on PEG 6000 solution. The accumulation of raw matter of seedlings was much more active than the pre-treatment of soft wheat seeds with solutions of ubiquinone, MgSO4, and a combination of vitamin E-ubiquinone.