The Role of Alternative Splicing in Polyploids in Response to Abiotic Stress

Alternative splicing (AS) is a crucial post-transcriptional regulatory mechanism that enhances transcriptomic and proteomic diversity by generating multiple mRNA isoforms from a single gene. In plants, AS plays a central role in modulating growth, development, and stress responses. We summarize the prevalence and functional roles of AS in plant development and stress adaptation, highlighting mechanisms that link AS to hormone signaling, RNA surveillance, and epigenetic regulation. Polyploid crops, with their duplicated genomes, exhibit expanded AS complexity, contributing to phenotypic plasticity, stress tolerance, and adaptive evolution. Thus, this review synthesizes current knowledge on AS in plants, with a focus on three economically important polyploid crops-Brassica napus, Gossypium hirsutum, and Triticum aestivum. We also discuss how subgenome interactions shape diversity in polyploids and influence trait variation. Despite significant advances enabled by high-throughput sequencing, mechanistic studies that directly link specific AS events to phenotypic outcomes remain limited. Understanding how polyploidy reprograms AS and how isoform variation contributes to stress adaptation will be critical for harnessing AS in crop improvement.