Phytase activity in tobacco (Nicotiana tabacum) root exudates is exhibited by a purple acid phosphatase

Elevated phytase activity was detected in tobacco root exudates in response to phosphorus starvation. The enzyme was purified to homogeneity and its identity was confirmed to be a purple acid phosphatase by molybdate-inhibition assay and cDNA cloning. Its catalytic properties implicate a specific role in mobilizing organic phosphorus in soil.