Transcriptomic Analysis of Cucumis hystrix and the Functional Identification of ChTrxh under NaCl Stress

Salinity is a prominent environmental stressor that significantly impacts plant growth and development. Here, we conducted research on the physiological and transcriptomic mechanism of a wild cucumber, Cucumis hystrix Chakr, under NaCl stress. Physiological data showed that contents of malondialdehyde, peroxide (H2O2), proline, soluble sugar, and activities of antioxidant enzymes of superoxide dismutase, peroxidase, ascorbate peroxidase, and glutathione reductase in wild cucumber plants were increased significantly after NaCl treatment. Transcriptomic analysis revealed that 3509 transcripts were differentially expressed in leaves and 5516 transcripts in roots after NaCl treatment. Numerous genes were related to the signal transduction, transcription factor, ion transport, osmotic metabolism, and reactive oxygen species scavenging. Moreover, the thioredoxin H type gene of Cucumis hystrix Chakr (ChTrxh) was isolated and characterized. Our study demonstrated that the transgenic tobacco plants overexpressing ChTrxh exhibited enhanced tolerance to NaCl stress compared to wild-type plants. These findings contribute valuable insights into the functional characteristics of important genes in wild cucumber under NaCl stress.