A Dof-CLE circuit controls phloem organization

Nat Plants. 2022 Jul;8(7):817-827. doi: 10.1038/s41477-022-01176-0. Epub 2022 Jul 11.


The phloem consists of sieve elements (SEs) and companion cells (CCs). Here we show that Dof-class transcription factors preferentially expressed in the phloem (phloem-Dofs) are not only necessary and sufficient for SE and CC differentiation, but also induce negative regulators of phloem development, CLAVATA3/EMBRYO SURROUNDING REGION-RELATED25 (CLE25), CLE26 and CLE45 secretory peptides. CLEs were perceived by BARELY ANY MERISTEM (BAM)-class receptors and CLAVATA3 INSENSITIVE RECEPTOR KINASE (CIK) co-receptors, and post-transcriptionally decreased phloem-Dof proteins and repressed SE and CC formation. Multiple mutations in CLE-, BAM- or CIK-class genes caused ectopic formation of SEs and CCs, producing an SE/CC cluster at each phloem region. We propose that while phloem-Dofs induce phloem cell formation, they inhibit excess phloem cell formation by inducing CLEs. Normal-positioned SE and CC precursor cells appear to overcome the effect of CLEs by reinforcing the production of phloem-Dofs through a positive feedback transcriptional regulation.

MeSH terms

  • Arabidopsis Proteins* / genetics
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / metabolism
  • Membrane Proteins / metabolism
  • Meristem / metabolism
  • Peptides / metabolism
  • Phloem / metabolism


  • Arabidopsis Proteins
  • CLE45 protein, Arabidopsis
  • Membrane Proteins
  • Peptides