Transcriptome Analysis of Maize under Salt Stress and Overexpression of ZmHSP20 Gene Confers Salt Tolerance in Tobacco

Soil salinity and alkalinity present a serious threat to global agriculture. The objective of this study is to elucidate candidate genes associated with salt stresses in maize plant tissues through the utilization of transcriptome and transgene methods. Specifically, 8723 and P138 maize cultivars were employed as salt-tolerant and salt-sensitive materials, respectively. To verify the salt tolerance of maize materials and screen the best salt stress experimental concentration, different concentrations of salt stress treatment were carried out. Then, transcriptome analysis was performed based on the sequence data of seedlings and the salt tolerance related genes were identified. The findings revealed that high salt concentrations significantly inhibited the germination characteristics and seedling growth of maize. Notably, the gene expression profiles in response to salt stress differed between the two maize inbred lines during the seedling stage. After the functional enrichment and co-expression interaction network analysis, we found that ZmHSP20 was a key gene that related to salt tolerance. In order to further verify the function of ZmHSP20, we constructed ZmHSP20 overexpression lines. The results showed that ZmHSP20 carrying tobaccos were more salt tolerant than the wild-type (WT). Additionally, the activity of antioxidant enzymes was significantly higher in the ZmHSP20 tobacco seedlings than in the WT. This study lays the groundwork for further research on the functional aspects of ZmHSP20 and presents an initial exploration of its role in conferring resistance to salt stress. Further investigations are required to reveal the mechanism by which ZmHSP20 regulates resistance against salt stress in maize and tobacco.