A key response of grain yield and superoxide dismutase in maize (Zea mays L.) to water deficit stress

To assess the grain yield, plant height and superoxide dismutase (Cu/Zn-SOD) activity, and its expression responses of maize to water deficit stress, a field experiment using a split-plot design based on randomized complete block design was performed with three maize hybrids, SC704, SC720 and NS640, under control and water-deficit stress conditions at the Research Station of University of Tabriz, Iran. The results indicated that water deficit stress reduced grain yield and plant height. Electrophoretic analysis for Cu/Zn-SOD based on sensitivity to KCN and H2O2 inhibitors was carried out using 8% slab polyacrylamide gels. The gene expression of Cu/Zn-SOD by using Real-time PCR in maize hybrids showed that water deficit stress increased Cu/Zn-SOD expression. SC704 with higher grain yield, plant height and Cu/Zn-SOD activity ranked as a drought-tolerant hybrid in this study. It can be concluded that the increase in Cu/Zn-SOD expression may decrease damage caused by water-deficit stress in maize.