Molecular cloning and functional characterization of a Cu/Zn superoxide dismutase gene (CsCSD1) from Cucumis sativus
Superoxide dismutase (SOD) proteins, which are widely present in the plant kingdom, play vital roles in response to abiotic stress. However, the functions of cucumber SOD genes in response to environmental stresses remain poorly understood. In this study, a SOD gene CsCSD1 was identified and functionally characterized from cucumber (Cucumis sativus). The CsCSD1 protein was successfully expressed in E. coli, and its overexpression significantly improved the tolerance of host E. coli cells to salinity stress. Besides, overexpression of CsCSD1 enhanced salinity tolerance during germination and seedling development in transgenic Arabidopsis plants. Further analyses showed that the SOD and CAT (catalase) activities of transgenic plants were significantly higher than those of wild-type (WT) plants under normal growth conditions as well as under NaCl treatment. In addition, the expression of stress-response genes RD22, RD29B and LEA4-5 was significantly elevated in transgenic plants. Our results demonstrate that the CsCSD1 gene functions in defense against salinity stress and may be important for molecular breeding of salt-tolerant plants.
KeywordsCucumis sativus Superoxide dismutase (SOD) Cu/ZnSOD Salinity stress Reactive oxygen species (ROS)
This work was funded by the Key Project of Youth Science Foundation of Jiangxi Province (20171ACB21025), the National Natural Science Foundation of China (31460522 and 31660578).
YZ and SL proposed the ideas and designed the experiments. YZ, LH, SY, LJ and SL performed the experiments. YZ and SL participated in the data analysis and wrote the paper. SY and SL helped to revise the paper. SL secured the funds to support this research. All authors read and approved the final manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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