Acts as a peptide hormone recognized by receptors (e.g. RGI1 and RGI2) to trigger signaling events including the regulation of RITF1 expression and leading to the production of reactive oxygen species (ROS) in roots to modulate meristem size. Signaling peptide (root growth factor) that maintains the postembryonic root stem cell niche in a PIN2-traffic dependent manner by regulating the expression levels and patterns of the transcription factor PLETHORA (PLT), mainly at the post-transcriptional level. Maintains the postembryonic root stem cell niche by regulating the expression levels and patterns of the transcription factor PLETHORA (e.g. PLT1 and PLT2), mainly at the post-transcriptional level. Influences circumferential cell number in the root meristem in response to Pi-deprivation. Regulates the pattern of root growth and lateral root development by modulating the length and the number of cortical cells in the root apical meristem (RAM), and the anticlinal asymmetric cell divisions in lateral root initiation cells.

> 85% as determined by SDS-PAGE.