Transcriptome profiling provides preliminary molecular insights into adventitious bud formation in herbaceous peony (Paeonia x 'Coral Charm')

Herbaceous peony is a kind of perennial herbaceous flowering plant and most varieties are highly dependent on ramet propagation. Some varieties, such as Paeonia x 'Coral Charm', have characteristics of relatively easy root cutting propagation. However, underlying adventitious buds of root cutting, the molecular mechanisms are still not completely understood. Here, we collected four key stages of adventitious bud formation of P. x 'Coral Charm' for transcriptome sequencing, and assembled and annotated 326,139 transcripts. By carrying out weighted gene co-expression network analysis, three functional modules and several biological and metabolic pathways related to the adventitious bud formation were identified. Finally, we determined six transcription factors in the MYB, HD-ZIP, C2H2 and bZIP gene family that may play a key role in the adventitious bud formation. These results provided insights into the adventitious bud formation of herbaceous peony, and laid a theoretical foundation for the rapid propagation of Paeonia.