Abstract
Key message Expression analysis of Larix kaempferi mature miR171s and their primary transcripts and target gene LaSCL6 during somatic embryogenesis revealed the transcriptional and post-transcriptional regulation of the miR171- LaSCL6 module. Abstract Somatic embryogenesis provides a useful experimental system for studying the regulatory mechanisms of plant development. The level and activity of microRNA171 (miR171) fluctuate during somatic embryogenesis in Larix kaempferi , but the underlying mechanisms are still unclear. Here, in L. kaempferi we identified five members of the miR171 family, which cleave LaSCL6 mRNA at different sites. In addition, we improved the method of measuring miRNA activity in a more direct way. Furthermore, we measured the expression patterns of mature miR171s and their primary transcripts during somatic embryogenesis in L. kaempferi and found that their patterns differed, indicating that the transcription of MIR171 genes and the subsequent cleavage of their intermediate products are regulated. Taken together, our findings not only offer a means to study the regulation of miRNA activity, but also provide further insight into the regulation of L . kaempferi somatic embryogenesis by miR171- LaSCL6 .