Signaling peptide (root growth factor) that maintains the postembryonic root stem cell niche in a PIN2-traffic dependent manner (PubMed:20798316, PubMed:23370719). Root growth factor that 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 (By similarity). Influences the longitudinal growth rate in the primary root in response to phosphate ion (Pi)-deprivation (PubMed:25856240). Binds to LRR receptor-like serine/threonine-protein kinases RGI1, RGI2 and RGI3 to trigger their dimerization with SERK proteins and subsequent signaling. Expressed in root tips. In roots, expressed only in the quiescent center (QC), the columella stem cells (CC) and the innermost layer of central columella cells; mostly present in the second, third and fourth CC layers, at a lower level in undifferentiated CCs, but not, or only marginally, in the QC (PubMed:20798316, PubMed:23370719). Induced early during lateral root formation (PubMed:23370719). Accumulates in both root epidermis and cortex after Pi- deprivation. No visible phenotype, due to the redundancy with other RGF genes (PubMed:20798316, PubMed:23370719). Slower root growth after (Pi)-deprivation (PubMed:25856240). Triple mutant rgf1-rgf2-rgf3 shows a decreased meristematic cell number resulting in a short root phenotype associated with an altered PIN2 traffic (PubMed:20798316, PubMed:23370719). 'Golven' means irregular waves in Dutch. Belongs to the RGF family.