磷酸钠对粉红单端孢离体生长和细胞壁降解酶分泌的影响

目的 探讨外源磷酸钠对粉红单端孢（Trichothecium roseum, T. roseum）菌丝生长、孢子超微结构及分泌细胞壁降解酶活性的影响。方法 同一浓度的T. roseum孢子悬浮液等量接种到含不同质量浓度的磷酸钠（0.12、0.25、0.50、1.00、2.00 mg/mL）培养基中恒温培养，并定期测定菌落直径。制备孢子悬浮液用于孢子表面形态和超微结构观察及细胞壁降解酶活性测定。结果 磷酸钠处理明显抑制了T. roseum的菌丝生长，扫描电镜和透射电镜结果显示，磷酸钠明显抑制了T. roseum孢子生长，表现为表面粗糙且皱缩凹陷，同时孢子的超微结构发生了不规则变化。此外，磷酸钠还显著抑制了培养2 d后T. roseum分泌的果胶裂解酶、多聚半乳糖醛酸酶、多聚半乳糖醛酸转移消除酶、果胶甲基反式消除酶、果胶甲基半乳糖醛酸酶和纤维素酶活性。结论 磷酸钠处理可直接抑制T. roseum生长，并有效抑制其分泌细胞壁降解酶的活性。

Effects of trisodium phosphate on in vitro growth and cell wall degrading enzyme secretion of Trichothecium roseum

Objective To explore the effects of exogenous trisodium phosphate on hyphal growth, ultrastructure of Trichothecium roseum (T. roseum) spore, and the changes of cell wall degrading enzymes activities in vitro. Methods The same concentration of T. roseum was inoculated in equal quantities into the medium containing sodium phosphate of different mass concentrations (0.12, 0.25, 0.50, 1.00, 2.00 mg/mL) for constant temperature culture, and the colony diameter was determined periodically. Spore suspension was prepared for observation of spore surface morphology, ultrastructure and determination of cell wall degradation enzymes activity. Results Data from this study demonstrated that trisodium phosphate distinctly suppressed hyphal growth of T. roseum. Scanning electron microscopy and transmission electron microscopy results showed that trisodium phosphate strongly inhibited spore growth, as indicated rough surfaces and shrinking. The ultrastructure of the spores treated with trisodium phosphate was irregularly changed. Moreover, trisodium phosphate had a significant suppression effect on pectate lyase, polygalacturonase, polygalacturonic acid transeliminase, pectin methyl transeliminase, pectin methyl-galacturonase, and cellulose activities secreted by T. roseum after incubation for 2 d. Conclusion These findings suggest that trisodium phosphate has direct antifungal ability on T. roseum growth and effectively inhibits secretion of cell wall degrading enzymes.