Evolution of vascular plants through redeployment of ancient developmental regulators (bioRxiv)

Land plants (Tracheophytes), utilize the well-developed vascular tissue for conducting water and other nutrients necessary for plant growth. In Arabidopsis and other land plants, the key player of vascular cell division is well characterized and this includes the TMO5-LHW (TARGET OF MONOPTEROS 5 – LONESOME HIGHWAY) heterodimerization, downstream of auxin signaling. Loss of either one of the basic Helix Loop Helix (bHLH) transcription factors leads to reduced cell division during vascular development. In this paper, Hofland et al. identified the evolutionary conservation of TMO5 – LHW dimerization using the genomics data from onekp project and determined heterdimerization of potential orthologs. Through complementation assays in planta the authors have shown that TMO5-LHW dimerization, which promotes cell division necessary for vascular development, evolved during the origin of land plants. (Summary by Suresh Damodaran) bioRxiv 10.1101/650358