| description |
Small non-coding RNAs (sncRNAs) are emerging as key regulators of embryogenesis. To investigate the roles of sRNAs in regulating synchronism of somatic embryogenesis in Larix leptolepis, we deciphered the endogenous "sRNAome" in synchronous and desynchronous embryos. The 24-nt class sRNAs were overrepresented in both synchronous embryos and desynchronous embryos, accounting for 85.29% and 44.79%. A total of 29 miRNAs were upregulated in synchronous embryos, whereas 59 miRNAs were upregulated in desynchronous embryos. We describe the emerging theme for sncRNAs function: inhibiting the precocious expression, thus regulating the synchronism of somatic embryogenesis.These findings indicate that larch and possibly other gymnosperms have complex mechanisms of gene regulation involving sRNAs and miRNAs operating transcriptionally and post-transcriptionally during the regulation of synchronism.Overall design: One embryogenic cell line of Japanese larch (Larix leptolepis), designated as D878, with a high embryo maturation capacity was used in this study.Embryogenic callus was induced from immature embryos of Japanese larch on induction medium followed by sub-culture. Calli at the proembryogenic mass III stage were cultured on maturation medium in a dark environment at 25 ± 2°C. Samples were cultured on ABA-plus or ABA-minus maturation medium for 45 days. All samples were snap-frozen in liquid nitrogen, and stored in liquid nitrogen until RNA extraction. |