Transcriptomic insights into the role of miR394 in the regulation of flowering time in Arabidopsis thaliana

The initiation of flowering is a highly coordinated process that requires synchronization of endogenous plant developmental program with environmental signals through a complex interplay of genetic regulatory networks. The developmental shift from vegetative to reproductive stage is controlled by multiple flowering pathways, which together with other signals participate in the orchestration of flowering time regulation. Collectively, the different pathways converge to modulate the expression of key floral integrator genes, which subsequently trigger the expression of genes related to the differentiation of the vegetative shoot apical meristem into a flower meristem with the subsequent development of floral organs. We had previously demonstrated a role for miR394 in the regulation of flowering time, since mir394a mir394b double mutant plants harboring T-DNA insertions in the two MIR394 Arabidopsis genes exhibited an early flowering phenotype correlated with modified expression of flowering genes. In the present study we provide transcriptomic data and histological staining of reporter lines to give further insight into the role of miR394 in the regulation of flowering time in Arabidopsis thaliana and present an initial bioinformatic characterization of a newly identified lncRNA, which is found partially overlapping the MIR394B locus, and therefore we named MIR 394B- AS SOCIATED T RANSCRIPT ( MIRAST ). We identified differential domains of expression during flower development, which together with the transcriptomic analysis allows us to propose a role for miR394 in the fine tuning of Arabidopsis flower development through the regulation of transcription factors and chromatin remodeling factors.