This research aimed to study the expression of genes that are known for their importance in plant tolerance to low temperatures. The study was conducted in dry maize seed and subjected to sub optimal germination temperature. Four lines of maize seeds were used, two being classified as susceptible to low temperature (44 and 54) and two tolerant to low temperature (64 and 91). Water content and germination tests were performed at different temperatures (10 and 25°C) to evaluate the physical and physiological quality of maize seeds. For molecular study activity of heat-resistant proteins, esterase, superoxide dismutase, catalase and α-amylase enzymes were assessed. Study of AOX1, ZmMPK5, SOD, APX, SAD, ENR and LEA genes with real time PCR were carried out. AOX, SAD and LEA genes that are related as tolerant to abiotic stress showed higher expression in line 64, which was classified as tolerant to low germination temperature. The ZmMPK5 gene is associated with increased production of abscisic acid was expressed more in line 54, which was considered as susceptible to low germination temperature.

Keywords: Zea mays, seed vigor, abiotic stress.