TITLE Phosphate starvation induction of acid phosphatase in Ulva lactuca L. (Ulvales, Chlorophyta)
AUTHOR Tse-Min Lee
Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
FULL TEXT [in HTML format] [in PDF format]
ABSTRACT The relationships among specific growth rate, intracellular inorganic phosphate (Pi) concentrations, total phosphorus (P) concentrations and specific activities of acid phosphatase (ACP; EC 3.1.3.2) and alkaline phosphatase (AP; EC 3.1.3.1) were studied in a green marine macroalga Ulva lactuca L. after 4 days of incubation at 1, 15 or 30 然 NaH2PO4. Both the specific growth rate and the intracellular Pi and total P concentrations increased with increasing NaH2PO4 levels; a linear correlation with specific growth rate was found for both intracellular Pi concentrations (r2=0.78, P<0.05) and the total P concentrations (r2=0.83, P<0.05). The growth rate and the Pi and total P concentrations were relatively low at 1 然 NaH2PO4, indicating U. lactuca L. could be P-deficient at 1 然 NaH2PO4. The specific activity of ACP was 4 to 10-fold greater than that of AP. Exposure to 1 然 NaH2PO4 increased the specific activity of ACP but slightly decreased that of AP. The ACP specific activity was inversely correlated with specific growth rate (r2=0.72, P<0.05) and also intracellular Pi concentrations (r2=0.80, P<0.05) and the total P concentrations (r2=0.64, P<0.05). The AP specific activity had no correlation with specific growth rate, intracellular Pi concentrations, or total P concentrations. The addition of NaH2PO4 concentrations higher than 20 然 to the assay mixture inhibited the specific activities of both ACP and AP. Overall, the P deficiency induction of ACP activity is related to a decrease in P availability in U. lactuca L.
KEYWORD Acid phosphatase; Algae; Alkaline phosphatase; Phosphate starvation; Ulva lactuca;
ARTICLE INFO Botanical Bulletin of Academia Sinica, Volume 41 Number 1 January 2000, page 19-25, 7 pages
PUBLISHER Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China