SAD1 dynamically regulates alternative splicing and stress tolerance

Although Sm-like proteins (LSMs) form the core of U6 RNPs and function in pre-mRNA splicing, little is known regarding their regulatory role in selection of splice sites, alternative splicing (AS) and splicing efficiency in eukaryotes. The Arabidopsis SAD1 locus encodes the LSM5 protein and was defined in a genetic screen for components that regulate the expression of stress-responsive gene. To further investigate regulatory role of the protein SAD1 in pre-mRNA splicing, we performed RNA sequencing (RNA-seq) to examine the changes of the global alternative splicing (AS) among the wildtype Arabidopsis plant (C24), the mutant plant (sad1) and the sad1-overexpressed plant (SAD1-OE). Our work not only provided novel insights into the regulatory role of SAD1 or LSM proteins in splicing, but also provided new cues to improving splicing efficiency and optimizing biological functions and screening the stress-resistant plant.