Genome-wide analysis of alternative splicing events during response to drought stress in tomato (Solanum lycopersicum L.)

Alternative splicing (AS) is a post-transcriptional regulatory mechanism that expands proteomic diversity. AS often occurs in the context of changing environmental conditions. Nevertheless, it remains largely unknown whether or how AS is involved in plant responses to drought stress. To assess the effects of drought stress, we compared AS genes in tomato plants by constructing three RNA-seq libraries in normal and drought conditions. We identified 464 Stage 1 (normal condition)-specific, 512 Stage 2 (mild drought stress)-specific and 506 Stage 3 (drought stress)-specific AS genes. Stage-dependent changes in AS genes assigned to ‘response to stimulus’ may participate in plant tolerance to drought stress. Analysis of differential isoform expression of selected genes suggested that an AS event in the ubiquitination pathway may be required to control plant responses to drought stress. Taken together, these findings suggest that genes with specific-AS patterns may serve as potential genetic resources for future improvement of plant adaptation to drought stress.