Structural Characterization and Expression Analysis of SmCSD1 Gene in Eggplant (Solanum melongena)

Abstract

Superoxide dismutases (SODs) are crucial for plants for stress tolerance. They convert the superoxide anion into oxygen and hydrogen peroxide, providing the first line of defense against reactive oxygen species (ROS). SmCSD1 isolated from Solanum melongena L. belongs to the plant Cu/ZnSOD superfamily and shares high homology with Cu/ZnSODs in potato and tomato by protein sequence analysis. It was predicted SmCSD1 is located in the cytoplasm. Based on the quantitative RT-PCR tissue expression pattern analysis revealed that SmCSD1 constitutively expressed in eggplant. Its highest expression is in flowers, moderate—in leaves and stems, lowest—in roots. Meanwhile, analysis of the expression of SmCSD1 and the activities of SOD and Cu/ZnSOD under ABA treatment and different stress treatments, including salt, drought and low temperature, indicated that SmCSD1 was a stress-responsive gene, especially to salt and drought. Undoubtedly these results provide useful information for studying the mechanism of the resistance to abiotic stress and the function of SmCSD1 in antioxidant defense in eggplant.