小麦叶片β-1,3-葡聚糖酶的诱导、纯化与抗菌活性

Induction, Purification andAntifungalActivity of β-1,3-glucanase from Wheat Leaves

三个小麦品种331、抗倒680和鲁麦23经氯化汞、水杨酸或核黄素处理后，叶片中的β-1，3-葡聚糖酶活性均有不同程度的升高。氯化汞处理24h对品种331该酶活性的诱导作用最强。因此取用氯化汞处理24h的331小麦叶片研磨得到粗酶液。将粗酶液经硫酸铵分级沉淀、Phenyl-Sepharose Fast Flow疏水层析、DEAE-Sepharose Fast FloW阴离子交换层析和SephacrylS-100分子筛层析，得到了SDS-PAGE凝胶电泳谱带单一的β-1，3-葡聚糖酶样品。经SDS-PAGE(12％)和凝胶过滤层析，测得其分子量约为52.0～53.6kD。抗菌试验测定显示，纯化的β-1，3-葡聚糖酶对供试的4种病原真菌的生长、孢子萌发或芽管伸长都有一定程度的抑制作用。

Treatment with mercuric chloride (0.01%), salicylic acid(10.0 mg/mL) or ribofla- vin(1 mmol/L) induced the β-1,3-glucanase ac- tivity in all the three wheat varieties i.e. 331, Kangdao 680 and Lumai 23 tested, with the strongest inductive effect on variety 331 by treat- ment with mercuric chloride(0.01%) for 24 h (Figs.1-3). From leaves of variety 331 treated with mercuric chloride(0.01%) for 24 h, a kind of β-1,3-glucanase was purified by fractional pre- cipitation with ammonium sulphate, Phenyl- Sepharose chromatography(Phenyl-Sepharose Fast Flow), ion-exchange chromatography (DEAE-Sepharose Fast Flow) and gel-filtration chromatography (Sephacryl S-100) (Table 1). Through SDS-PAGE and gel filtration, the mo- lecular weight of the purified β-1,3-glucanase was determined to be about 52.0-53.6 kD (Fig.-4). The purifie β-1,3-glucanase showed antifun- - gal activity against both Alternaria longipes and ,Rhizoctonia cerealis on tested plates (Figs.5,6), and inhibited the germ tube elongation and spore -germination of Verticillium dahliae and Fusarium omysporum f.sp cucumerinum (Figs.7,8).