Objective: To investigate the functional roles of PHO112 in Candida albicans phytase activity, hyphal development, and virulence. Methods: C. albicans PHO112 null mutants were created by a PCR-based gene targeting method using gene-specific primers. C. albicans PHO112 reintegrants were created by transforming the full length PHO112 gene into the C. albicans PHO112 null mutants. Phytase activity in C. albicans PHO112 null mutants was determined by quantifying the amount of released inorganic phosphate from sodium phytate using ammonium molybdate. The ability to form hyphae was evaluated in YPD medium supplemented with 10% fetal bovine serum at 37oC (hyphal-inducing conditions). Adhesion to buccal epithelial cells (BECs) was evaluated by counting the number of attached fungal cells to Gram’s stained BECs under light microscope. Fungal pathogenicity was determined using reconstituted oral human epithelial (ROHE) tissues, and histological changes of the tissues were observed under light microscope after staining with hematoxylin and eosin. Results: C. albicans PHO112 null mutants were created and verified by PCR and genomic Southern hybridization. C. albicans PHO112 null mutants exhibited the following phenotypic properties (P \u3c 0.05) with respect to the wild type counterparts: (1) a reduction of ~25% of phytase activity; (2) a reduction of ~22% of hyphal growth under hyphal-inducing conditions; (3) a reduction of ~22% of adhesion to BECs; and (4) an inability to infect ROHE tissues. Conclusions: The collective data of the present study suggest that C. albicans PHO112 contributes to phytase activity, hyphal development, and fungal virulence. The ability to inhibit the novel virulence trait may provide another antifungal strategy in the fight against this common human fungal pathogen in clinical settings
