The effect of SEAP1 on the accumulation of miRNAs and mRNAs

SE-Associated Protein 1 (SEAP1), is a conserved protein in eukaryotes. Its orthologs, SART3 and PRP24 from metazoans and yeast play essential roles in splicing. Here, we report that SE-Associated Protein 1 (SEAP1), is required for miRNA biogenesis in Aradopsis. Lack of SEAP1 causes embryo lethality and knockdown of SEAP1 by an artificial miRNA (amiRSEAP1) causes pleiotropic growth defects and reduction in miRNA accumulation, accompanied with increased levels of target transcripts. SEAP1 associates with the RNase III enzyme Dicer-like 1(DCL1) complex, which processes primary miRNA transcripts (pri-miRNAs) into miRNAs, and seems to promote the interaction of the DCL1 complexes with pri-miRNAs. SEAP1 is also required for pri-miRNA accumulation. However, it does not affect the transcription of pri-miRNAs, suggesting it may indirectly or directly stabilize pri-miRNAs. SEAP1 also affects the spicing of pri-mRNAs. These results suggest that SEPA1 promotes miRNA biogenesis by positively modulating pri-miRNA splicing, processing and stability. We also find that intron retention in amiRSEAP1 is altered at global levels, linking SEAP1 to spicing. Collectively, our results uncover the function of SEAP1 in plants. To exam the effect of artifical miRNA targeting to SEAP1 on the accumation of miRNAs by RNA Sequencing Non-coding RNA Deep Sequencing