Genome-Wide Analysis of Alternative Splicing Events Responding to High Temperatures in Populus tomentosa Carr.

Abstract

Through alternative splicing (AS) processes, eukaryotic genes can generate a variety of transcription isoforms that lower the expression levels of the normal transcripts or result in diversity in the genes’ activities. Then, AS plays a significant role in the control of plant development and stress tolerance. In this study, we analyzed Populus tomentosa Carr. TC1521’s AS episodes in response to high temperatures. The samples treated at 25 °C, 30 °C, 35 °C, and 40 °C produced a total of 10,418, 11,202, 9947, and 14,121 AS events, respectively, which responded to 4105, 4276, 4079, and 4915 genes, respectively, representing 9.84%, 10.25%, 9.78%, and 11.78% of the total number of transcribed genes, respectively. The most common AS pattern, accounting for 42.31% to 51.00% of all AS events, was intron retention (IR), followed by exon skipping (ES), which accounted for 9.14% to 10.23% of all AS events. respectively. According to sequence characterization, AS was negatively correlated with guanine-cytosine content (GC content) but favorably correlated with intron length, exon number, exon length, and gene transcription level. Compared to treatment at 25 °C, 2001 distinct AS genes were discovered at 40 °C. They were primarily enriched in the RNA degradation pathway and the valine, leucine, and isoleucine degradation route, according to (gene ontology) GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. These findings demonstrated how the AS process might be severely impacted by high temperatures. In addition, the information on AS isoforms helped us comprehend stress-resistance mechanisms in new ways and completed molecular design breeding.