Higher plants, including Zea mays, exposed to excess heat, at least 5 °C above their optimal growing conditions, exhibit a characteristic set of cellular and metabolic responses required for the plants to survive under the high-temperature conditions. These effects caused many physiological changes in mobilization of seed reserve substances and starch consump-tion for germination. The starch content is one of the main quality indicators of maize seeds. The function of starch as reserve polysaccharides, is to supply energy to the immature, non-photosynthetic plantlets that occurs during the seed germination. The study of changes in reserve substances mobilization, including used starch, during germination of intact and heat shocked seeds could provide the possibility to development the rapid procedure of evaluation the intrinsic resistance of seeds to non optimal temperatures. Knowledge about the mobili-zation of reserve substances from maize hybrids selected in the Republic of Moldova during germination and their modification under influence of high temperature and natural regulators of growth is very limited. In this regard, the purpose of this work was to study the changes in starch content in correlation with reserve substances mobilization for the germination of maize seeds under the influence of supraoptimal temperature and genistifolioside as a natural regulator of growth.