Transcriptome analysis reveals molecular mechanisms for salt tolerance in wheat (Triticum aestivum L.)

Soil salinity is a crucial abiotic stressor with substantial impacts on the growth and yield of wheat (Triticum aestivum L.). Thus, exploration of genes related to salinity tolerance is essential for wheat breeding. Here, we treated the seedlings of Bima4 and Xiaoyan22, two wheat varieties with significant differences in salt tolerance, in a greenhouse with 1.0 standard concentration artificial seawater, and collected the samples at six distinct time points (0, 1, 3, 6, 12, and 24 h) after salt stress treatment for temporal transcriptomic analysis. A total of 6688 and 11,842 differentially expressed genes were identified in Bima4 and Xiaoyan22, respectively. Salt-tolerant Xiaoyan22 exhibited more up-regulated genes at 3 and 24 h, while salt-sensitive Bima4 had more up-regulated genes at 6 h. Gene ontology and transcription factor enrichment analyses demonstrated substantial variations in salt tolerance pathways between the two varieties. By integrating the enrichment analysis results, 886 genes related to salt tolerance were identified, providing a foundation for experimental verification and enhancement of wheat salt tolerance. Additionally, 869 and 1095 differential alternative splicing events were detected in Bima4 and Xiaoyan22, respectively, and five salt stress-related genes identified underwent alternative splicing. In summary, this study improves our understanding of the molecular mechanisms underlying salt tolerance in wheat.