Phosphoinositide phosphatase that preferentially hydrolyzes PtdIns(4)P. Regulates the accumulation of PtdIns(4)P on membrane compartments at the tips of growing root hairs leading to proper root hair development. Associated to tip-localized membranes in growing root hairs (PubMed:18281508). Ubiquitous. By wounding. The phosphatase catalytic core motif (or RXNCXDCLDRTN motif) from the SAC domain is found in metal-independent protein phosphatases and inositol polyphosphate phosphatases. Short, bulged and branched root hairs. Accumulates elevated levels of PtdIns(4)P in roots.