MiRNA expression analysis during somatic embryogenesis in Coffea canephora

Somatic embryogenesis (SE) is a biological process by which somatic cells can be differentiated and undifferentiated by epigenetic reprograming. MicroRNAs (miRNAs), considered key regulatory elements during vegetative development, have been identified as essential players in early responses during the induction of SE. However, the role of these small molecules during SE in coffee is poorly understood. In the present work, 16 miRNAs from Coffea canephora were analyzed in detail from a total of 40 miRNAs candidates, and their possible role in the earlier stages of SE was analyzed. We found that miR164, miR168, miR535 and miR2119 were related to differentiation and the formation of the globular stage, while miR166, miR168, miR393, miR397, miR398, miR1524 and miR2119 were observed during the heart stage development. Also, it was revealed that among the target genes of those miRNAs are SQUAMOSA, LACCASE, CUP-SHAPED COTYLEDON, ARFs and other genes involved in cell division and differentiation. Our data suggest a differential and cooperative role for miR535, miR164, miR2119 and miR157a during the earliest stages of SE in C. canephora, supporting their regulatory role in the cellular totipotency of plants.