Converts oxidosqualene to thalianol. (S)-2,3-epoxysqualene = thalianol Expressed primarily in the root epidermis. Induced by gravity and light (PubMed:21252258). Transcriptional expression is repressed by CLB (PubMed:21252258). Loss of thalianol production in roots. Constitutes with three contiguous genes an operon-like gene cluster that is involved in the thalianol pathway. Belongs to the terpene cyclase/mutase family.