Transcriptome analysis of alternative splicing in peanut (Arachis hypogaea L.)

Jian Ruan, Feng Guo, Yingying Wang, Xinguo Li, Shubo Wan, Lei Shan, Zhenying Peng

Alternative splicing (AS) represents a mechanism widely used by eukaryotes for the post-transcriptional regulation of genes. The detailed exploration of AS in peanut has not been documented. The strand-specific RNA-Seq technique was exploited to characterize the distribution of AS in the four samples of peanut (FH1-seed1, FH1-seed2, FH1-root and FH1-leaf). AS was detected as affecting around 37.2% of the full set of multi-exon genes. Some of these genes experienced AS throughout the plant, while in the case of others, the effect was organ-specific. Overall, AS was more frequent in the seed than in either the root or leaf. The predominant form of AS was intron retention, and AS in transcription start site and transcription terminal site were commonly identified in all the four samples. It is interesting that in genes affected by AS, the majority experienced only a single type of event. Not all of the in silico predicted transcripts appeared to be translated, implying that these are either degraded or sequestered away from the translation machinery. With respect to genes involved in fatty acid metabolism, about 61.6% were shown to experience AS. Our report contributes significantly in AS analysis of peanut genes in general, and these results have not been mentioned before. The specific functions of different AS forms need further investigation.