New insights into microbial manipulation of the plant spliceosome

Alternative splicing (AS) has emerged as a regulatory layer in plant adaptation to the environment. In particular, biotic stresses trigger a drastic remodeling of the plant AS landscape, with minimal overlap with changes at the gene expression level, suggesting an additional, albeit poorly understood, mechanism of regulation. Recent studies have revealed that effectors from unrelated pathogens target core spliceosome components as well as accessory splicing factors. While this targeting is beginning to shed light on the relevance of the modulation of the plant AS landscape for pathogen invasion, it has also led to the identification of novel splicing factors, allowing the discovery of unexplored characteristics of the plant splicing machinery. Here, we review this emerging field, which delineates an additional battleground in the evolutionary arms race between plants and pathogens and has the potential to advance our biochemical and mechanistic understanding of the plant spliceosomal complex.