Abstract:To investigate the alleviation effects of exogenous hydrogen sulfide (H2S) on maize seeding growth under drought stress, maize inbred line Zheng 58 was employed and treated under nutrient solution with different concentrations (0, 0.3, 0.6, 0.9, 1.2 and 1.5 mmol·L-1) sodium hydrosulfide (NaHS) process maize seedlings under 15% PEG simulated drought stress. The optimal concentration of NaHS were also used to spray on the leaves of seedling, and to study the antioxidant enzyme activities, antioxidant content, free proline accumulation, reactive oxygen species (ROS) accumulation, and membranous peroxide level on seedlings. According to the results, under the drought stress, exogenous H2S treatment significantly improved the maize seed germination activity, germination rate and seedling biomass to some extent. After spraying 0.6 mmol·L-1 NaHS on the leaves, the antioxidant enzyme activities including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbic acid peroxidase (APX), and the content of ascorbic acid (ASA) and glutathione (GSH) were increased. Moreover, the delta 1-pyrroline-5-carboxylic acid synthetase (P5CS) activity and the free proline (Pro) content in the leaves were also increased. However, hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents had a significantly drop. These illustrated that the exogenous H2S regulated the antioxidant levels in leaves to reduce oxidative damage on maize seedling during drought stress that improved the maize seedling adaptability to drought stress. This study provided the basis for the further study of H2S function on maize drought stress response mechanism.