Regulation of LaSCL6 expression by genomic structure, alternative splicing, and microRNA in Larix kaempferi

SCR-LIKE-6 ( SCL6 ), a member of the GRAS transcription factor family, plays important roles in many aspects of plant growth and development. In a previous study, we showed that the post-transcriptional regulation of Larix ( La ) SCL6 by the microRNA miR171 functions in regulating the mode of cell division and the maintenance of embryogenic potential during somatic embryogenesis in larch. To investigate its expression pattern during tree aging, which has been studied by comparative transcriptomic analysis, we re-examined the annotation and expression of every transcript and found one that was longer; we annotated it as SCL6 , indicating that it might be a variant of LaSCL6 . To verify this, we cloned the DNA and cDNA sequences of this transcript and found that alternative splicing indeed occurred in its expression . Moreover, both variants were detectable in embryogenic cultures and several organs. Notably, the DNA sequence of LaSCL6 contained simple sequence repeats and a single-nucleotide polymorphism which might result in the expression of two variants with a change in their tertiary structures. Regulation of LaSCL6 by miR171 was also found. Taken together, the expression of LaSCL6 is controlled at several levels, and this study not only provides further information about the expression of LaSCL6 but also offers a means to study the regulation of gene expression.