Background: Suaeda glauca and Suaeda salsa have obvious morphological features and strongly tolerate saline-alkali environments. However, the mechanisms that lead to the differences in saline-alkali tolerance between them remain unclear.
Methods: In this study, we employed comparative transcriptome analysis to investigate S. glauca and S. salsa under saline-alkali stress.
Results: Our sequencing efforts resulted in the identification of 99,868 unigenes. We obtained 12,021 and 6227 differentially expressed genes (DEGs) from the S. glauca and S. salsa under salt stress compared with plants in the control. Notably, 1189 and 1864 were specifically upregulated DEGs in the roots and leaves of S. salsa under saline-alkali conditions, respectively. These genes were enriched in pathways such as "Plant hormone signal transduction", "Carbon metabolism" and "Starch and sucrose metabolism". Further analysis of stress-related pathways and gene expression levels revealed that key genes involved in abscisic acid (ABA) and jasmonic acid (JA) biosynthesis, ABA signal transduction, and their downstream transcription factors were upregulated in the roots of S. salsa under saline-alkali conditions. Additionally, 24 DEGs associated with stress response were identified in the roots and leaves of both species. The expression levels of these pathways and related genes were higher in S. salsa than in S. glauca, suggesting that S. salsa enhances its saline-alkali tolerance by elevating the expression of these genes.
Conclusions: This study provides a new research perspective for revealing the differences in saline-alkali tolerance mechanisms between S. glauca and S. salsa, bringing forth important candidate genes for studying their saline-alkali tolerance.
Keywords: Suaeda glauca; Suaeda salsa; comparative transcriptome; saline–alkali stress.