Positive effector of CLE45 peptide signaling (PubMed:27354416). Post-transcriptionally regulated amplifier of the CLE45 peptide signal that acts downstream of BAM3 in the regulation of the transition of root protophloem cells from proliferation to differentiation; thus preventing primary root elongation but stimulating lateral roots development (PubMed:27354416). Recruited to the plasma membrane upon CLE45 peptide application. Expressed in roots. Accumulates throughout roots vascular cylinders (PubMed:27354416). First observed early in the meristem, and later detected in procambial cells and phloem poles (PubMed:27354416). Absent from the xylem axis (PubMed:27354416). Strong accumulation in developing sieve elements upon CLE45 peptide application in a BAM3-dependent manner. Partial suppression of phenotypes observed in brx mutants such as reduced root growth and smaller root meristem size (PubMed:27354416). Reduced sensitivity to externally applied CLE45 peptides in term of root growth suppression (PubMed:27354416). Less stable in procambial than in phloem pole cells.