Transcription factor that regulates the development of root hairs (PubMed:19675148). Transcription factor that regulates the development of sperm cells (PubMed:28585562). Homodimer. Expressed constitutively in roots, leaves, stems, and flowers. Repressed by heat treatment. No visible phenotype under normal growth conditions (PubMed:19675148, PubMed:28585562). The triple mutant lrl1, lrl2 and lrl3 exhibit very short root hairs (PubMed:19675148). The double mutant drop1 and drop2 fail to develop sperm cells (PubMed:28585562).