The post-transcriptional regulation of LaSCL6 by miR171 during maintenance of embryogenic potential in Larix kaempferi (Lamb.) Carr.

Somatic embryogenesis provides an opportunity to explore the mechanisms underlying the determination of cell fate. In a previous study, differential levels of mature miR171 were found between embryogenic and non-embryogenic cultures and during somatic embryo maturation in Larix kaempferi (Lamb.) Carr. However, little is known about its target genes in these processes. Here, a full-length cDNA for the SCARECROW-LIKE 6 (SCL6) homolog from L. kaempferi, LaSCL6, was cloned. Sequence analysis showed that the miR171 target sequence was present in the LaSCL6 transcript. Isolation of the miRNA-guided cleavage products of LaSCL6 further suggested that this gene was being regulated by miR171. LaSCL6 transcript levels in embryogenic and non-embryogenic cultures and during the late stage of somatic embryo maturation were measured, and the results showed that cleavage of the LaSCL6 mRNAs occurred actively in embryogenic cultures. Based on the relationships between the expression patterns of LaSCL6 and mature miR171, we concluded that the post-transcriptional regulation of LaSCL6 by miR171 might participate in the maintenance of embryogenic potential, providing new insights into the regulatory mechanisms of somatic embryogenesis.