Abstract:The mitochondrial ultrastructure of wheat cell were investigated by transmission electron microscope under different simulated micro-environmental conditions. Simultaneously, mitochondrial O2-?, COX activity, seed vitality and the activity of antioxidative enzymes (SOD, CAT and POD) were measured, which were used to discuss the relationship between them and wheat aging at the micro perspective. The research showed that with the extension of storage time and increasing of temperature and humidity, mitochondria number was decreased, and the damage and deterioration of its ultrastructure became serious. The ultrastructure changed mainly as follows: outer membranes deformed, with broken and solution occurred; the number of internal ridges decreased, and the structure of its bilayer membranes gradually blurred; the inner mitochondria degraded and vacuolization occurred in inner cavity. At the same time, generation rate of O2-? kept increasing, COX activity and seed vitality kept decreasing. The three indexes had the most obvious variation under the conditions of 35 ℃ and 85% humidity. The activity of antioxidative enzymes in wheat cell all increased first and then decreased under high temperature and humidity (75% and 85%). The decreases of SOD, CAT and POD were more obvious under the conditions (35 ℃, 85%) than those under other conditions, being of 36%, 63% and 57% respectively.
