Transcription factor involved in the regulation of root hair elongation (PubMed:20139979, PubMed:27251390, PubMed:27452638). Is sufficient to promote postmitotic cell growth in root-hair cells and is a direct transcriptional target of RHD6 and RSL1 (PubMed:20139979). Involved in the regulation of root hair elongation in response to low phosphate (PubMed:27251390, PubMed:29651114). Controls root hair cell growth by regulating the expression of genes encoding proteins involved in cell signaling, cell wall modification and secretion (PubMed:27452638). Homodimer. Expressed constitutively in roots, leaves, and flowers (PubMed:12679534). Expressed in root epidermal hair cells (PubMed:20139979). Induced by jasmonate (JA) treatment (PubMed:31988260). Induced by low phosphate conditions (PubMed:27251390, PubMed:29651114). D-box [RxxLxxxN] motif functions as a recognition motif for the ubiquitination machinery. Ubiquitinated (Probable). Ubiquitination leads to its subsequent degradation by the 26S proteasome (PubMed:27251390). Strong reduction in root hair number, density and length in seedlings.