Comparative Analysis of Alternative Splicing Events in Foliar Transcriptomes of Potato Plants Inoculated with Phytophthora Infestans

Alternative splicing (AS) is a common process during gene expression of plants in coping various biotic or abiotic stresses. The work reports identification and analysis of AS events in foliar samples of two potato lines, including a wild type line and a pathogen resistant transgenic line (+RB), inoculated with Phytophthora infestans . After combining all RNA-seq data collected from 36 samples, a total of 10,246 AS events were identified, including 1,563 exon skipping, 1,368 alternative donor sites, 3,091 alternative acceptor sites, 884 intron retention, and 3,340 complex events, which consisted of more than one basic event. These AS events were generated from 45,874 isoform transcripts expressed from 13,704 genes. It was estimated 30.2% of genes undergoing AS in this analysis. Furthermore, we identified 406 specific AS events, which were generated from 281 genes, and 766 differentially expressed transcripts (DETs) in the sample collected 24 hours after inoculation of P. infestans in +RB lines. These DETs were expressed from 763 genes, and among them, 338 genes were alternatively spliced. These results indicate that both AS and differential gene expression may contribute to the resistance against P. infestans in +RB line of potato plants.