病原菌与植物互作过程中分泌的细胞壁降解酶具有致病和激发植物免疫的双重功能。BcGs1是从灰葡萄孢菌代谢物中分离的葡聚糖-1,4-α糖苷酶,能激发番茄和烟草的免疫防御反应,提高抗病性。BcGs1包含糖苷水解酶家族15(GH15)和糖结合模块家族20(CBM20)两个结构域,其激发植物防御反应的作用方式及功能结构域尚不清楚。本文测定了BcGs1不同诱导时间对提高番茄抗灰葡萄孢菌的效果、体外糖苷酶活性,并比较了BcGs1不同结构域截短蛋白与全长蛋白引起细胞坏死活性的差异。结果表明,BcGs1蛋白诱导番茄72 h可将灰葡萄孢菌引起的病斑面积减少23.25%;BcGs1能水解淀粉和海带多糖,但不能水解羟甲基纤维素和微晶纤维素;BcGs1全长、GH15和CBM20截短蛋白均能在烟草细胞中正常瞬时表达,但表达GH15的烟草叶片枯斑面积明显小于表达全长蛋白BcGs1的枯斑面积,表达CBM20截短蛋白的叶片没有产生枯斑反应;为了进一步明确截短蛋白GH15和全长蛋白BcGs1激发烟草细胞坏死活性的差异,用大肠杆菌表达并获得了纯化的重组蛋白GH15,叶片浸润法测定结果表明,截断蛋白GH15的细胞坏死活性仍然低于BcGs1全长蛋白的坏死活性,说明BcGs1诱导烟草细胞坏死活性需要GH15和CBM20结构域的共同参与。本文研究结果为进一步探讨BcGs1诱导植物抗病机制奠定了基础。 The cell wall degrading enzyme secreted by the interaction between pathogens and plants has the dual functions of pathogenicity and plant immunity. BcGs1 is a glucan-1,4-α-glucosidase isolated from the metabolites of Botrytis cinerea that stimulates the immune defense response of tomato and tobacco and enhances disease resistance. BcGs1 contains two domains of glycoside hydrolase family 15 (GH15) and carbohydrate binding module family 20 (CBM20), and its mode of action and functional domain for stimulating plant defense response are not yet clear. In this paper, the effect of different induction time of BcGs1 on the resistance to Botrytis cinerea in tomato and the activity of glucosidase in vitro were determined. The differences of the activity of truncated proteins and full-length proteins in BcGs1 were also compared. The results showed that BcGs1 could reduce the lesion area induced by Botrytis cinerea by 23.25% after induction by BcGs1 for 72 h. BcGs1 could hydrolyze starch and kelp polysaccharide, but could not hydrolyze hydroxymethylcellulose and microcrystalline cellulose. The truncated proteins of both GH15 and CBM20 were transiently expressed in tobacco cells. However, the area of ​​blight of tobacco leaves expressing GH15 was significantly smaller than that of BcGs1 expressing full - length protein, and the leaves expressing CBM20 truncated protein did not produce dead spots. In order to further clarify the difference between the truncated protein GH15 and the full-length protein BcGs1, the purified recombinant protein GH15 was expressed in E. coli and the leaf infiltration assay showed that the cell necrosis activity of the truncated protein GH15 was still lower than BcGs1 full-length protein necrosis activity, indicating that BcGs1 induced tobacco cell necrosis activity requires the co-participation of GH15 and CBM20 domains. The results of this study laid the foundation for further exploring the mechanism of BcGs1 induced plant disease.