PHOSPHATASE-ACTIVITIES AND PHOSPHORUS UPTAKE FROM INOSITOL PHOSPHATE BY ECTOMYCORRHIZAL FUNGI
PHOSPHATASE-ACTIVITIES AND PHOSPHORUS UPTAKE FROM INOSITOL PHOSPHATE BY ECTOMYCORRHIZAL FUNGI
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DOI：
10.1139/b92-101
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发表时间：
1992-04-01
期刊：
影响因子：
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通讯作者：
LINKINS, AE
中科院分区：
文献类型：
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作者：
ANTIBUS, RK;SINSABAUGH, RL;LINKINS, AE
为了更好地了解酸性磷酸酶活性的生理意义，我们研究了无机和有机磷生长源对几种外生菌根真菌的酶活性和P-32吸收的影响。4个担子菌种的8个菌株的菌丝体在pH值为4.5或5.0时表现出最高的对硝基苯基磷酸酶活性。柑橘硬皮病不同菌株和不同种间酸性磷酸酶活力不同。在天然聚丙烯酰胺凝胶中，全细胞提取物的同工酶图谱存在明显的种间差异。全细胞提取液中主要的磷酸酶等电点在pH 5.0~5.5范围内。真菌在六磷酸肌醇上的生长与在无机磷上的生长不影响两种方法检测的同工酶图谱。在所研究的物种中，六磷酸肌醇的生长不同程度地影响了它们对对硝基苯基磷酸和肌醇磷酸的表面活性和溶解活性。植酸酶活性足以在所有菌株中产生P的净释放。在所研究的五种植物中，有四种植物对六磷酸肌醇的生长与从肌醇多聚磷酸盐中摄取P-32的增加有关。用对硝基苯磷酸测定的酸性磷酸酶与P-32摄取呈正相关。六磷酸肌醇生长的菌丝体植酸酶活性降低与这种菌丝体的磷内流增加有关。磷酸酶活性和P-32吸收都受到无机磷抑制，其中P-32吸收表现出更高的敏感性。这些结果进一步证明了表面酸性磷酸酶在外生菌根真菌利用有机磷中的作用。
To better understand the physiological importance of acid phosphatase activity we examined the effects of inorganic and organic phosphorus growth sources on enzyme activity and P-32 uptake in several ectomycorrhizal fungi. Mycelium of eight isolates from four basidiomycete species demonstrated optimal p-nitrophenyl phosphatase activity at pH 4.5 or 5.0. Acid phosphatase activities varied between strains of Scleroderma citrinum and between the species examined. Interspecific differences in isozyme patterns of whole cell extracts were apparent in native polyacrylamide gels. The isoelectric points of the predominant phosphatases in whole cell extracts were in the pH 5.0 to 5.5 range. Growth of fungi on inositol hexaphosphate versus inorganic P did not affect the isozyme patterns detected by either electrophoretic method. Growth on inositol hexaphosphate affected surface and soluble activities towards p-nitrophenyl phosphate and inositol phosphate to different degrees in species examined. Phytase activity was sufficient to produce a net release of P in all isolates. Growth on inositol hexaphosphate was associated with increased uptake of P-32 from inositol polyphosphate in four of five species examined. Acid phosphatase, measured with p-nitrophenyl phosphate, was positively correlated with P-32 uptake. Decreased phytase activities measured for inositol hexaphosphate grown mycelium were associated with increased P influx in such mycelium. Both phosphatase activity and P-32 uptake were subject to inorganic P inhibition with P-32 uptake demonstrating a greater sensitivity. These results provide further evidence for the role of surface acid phosphatases in organic P utilization by ectomycorrhizal fungi.