Yunyun Li, Junru Mao, Song Kou
Plants have evolved sophisticated immune systems to defend against diverse pathogens, whereas pathogens deploy effectors to manipulate host cellular processes for successful infection. Recent studies have revealed that pathogen effectors can target host RNA processing, particularly pre-mRNA alternative splicing (AS), to reshape transcript isoform profiles and modulate plant immunity. However, the common principles and specific differences among pathogen effector-mediated regulation of host AS and their impacts on plant immunity have not been systematically summarized. In this review, we summarize recent advances in pathogen effector-mediated regulation of plant AS, focusing on three major mechanisms: targeting host splicing factors, altering RNA regulatory elements, and interfering with RNA-processing pathways. We discuss how effector-induced AS reprogramming affects immune-related gene expression and contributes to pathogen virulence. Furthermore, we highlight the emerging potential of AS regulation in disease resistance and disease-resistant crop breeding, and propose future directions for dissecting effector-specific splicing targets and translating AS-based regulatory mechanisms into crop improvement strategies. This review emphasizes host RNA splicing as an important regulatory layer in plant-pathogen interactions and provides new perspectives for understanding pathogen manipulation of plant immunity.