Uncovering the miRNA-mediated regulatory network involved in Ma bamboo () shoot organogenesis.

Bamboo is an important non-timber forest product and is well-known for its reluctance to regenerate. Recently we have established a shoot organogenesis (DNSO) protocol in Ma bamboo () and revealed the transcriptomic dynamics during Ma bamboo regeneration, which suggested the potential roles of Ma bamboo microRNAs (DlamiRNAs) in this process. However, how DlamiRNAs regulate bamboo DNSO is poorly understood. Here we performed integrated analysis with sRNAome, degradome, and transcriptome sequencing by using samples covering the four stages of the bamboo DNSO process. A total of 727 DlamiRNAs showed differential expression during the bamboo DNSO process, and the core DlamiRNA-DlamRNA- mediated regulatory networks for bamboo DNSO were constructed. Based on the results, DlamiR156 was selected for further functional characterization of its potential roles in bamboo DNSO. Transgenic bamboos with increased DlamiR156 levels exhibited an enhancement in their regeneration efficiency. Conversely, when DlamiR156 levels were downregulated, the regeneration efficiencies of transgenic bamboos decreased. Our findings show that the DlamiRNA-mediated regulatory pathways are significant in the process of bamboo regeneration and will contribute to our understanding of the molecular mechanisms governing plant organogenesis in a more comprehensive manner.