Global profiling of alternative splicing landscape responsive to salt stress in wheat ( Triticum aestivum L.)

Alternative splicing (AS) plays crucial roles during plant development especially in stress responses. Although many studies have been performed on AS, the function of which participating in abiotic stress responses is still not well known. To assess the interplay between AS and salt stress, genome-wide analyses of AS were performed. Totally, 11,141 genes were found exhibiting significant AS changes after salt stress treatment, and more AS events were identified in Chinese Spring (CS, salt-sensitive) (21,203) than in Qing Mai 6 (QM, salt-tolerant) (19,742). Meanwhile, wheat homeologous genes displayed differential AS responses under salt stress treatment, and 7235, 8143 and 7407 AS events were identified on subgenome A, B and D respectively. Comparison of AS events at different time after salt stress showed that 4747 and 4129 salt stress responsive AS events were characterized in CS and QM, respectively, and most AS events were induced at 48 h after salt stress (HAS) compared with the other three stages. Functional enrichment analysis found that abiotic stress responsive pathways tended to be enriched in partitioned differentially spliced genes (DSGs) between CS and QM after salt stress treatment, and Pfam classification showed that many stress related proteins were also enriched under salt stress condition. Thus, these results demonstrated that AS regulation may play key roles in response to salt stress, which, together with transcriptional regulation, contributes to abiotic stress tolerance in wheat.