An understanding of the evolutionary aspects of gene regulatory network (GRN) is fundamental to elucidate mechanisms of environmental adaptations; nevertheless, how the GRNs leading to land adaptation evolved remains poorly understood. In this study, we isolated a single IIIf bHLH TF from M. polymorpha, MpGL3. Transgenic M. polymorph ectopically expressing MpGL3 (referred to MpGL3ox) decreased the size and numbers of gemma cups, suggesting that MpGL3 is involved in the regulation of morphological development. Transcriptomics analysis of MpGL3ox was performed. Overall design: We made transgenic M. polymorpha that carries MpGL3 fused to citrione driven by constitutive expression promoter. We performed RNA-Seq of two independent lines and compared with wild type (Tak-1) with biologically triplicates.