Zhang Yi, Zhang Yunhua, Qiu Dewen, Zeng Hongmei, Guo Lihua, Yang Xiufen
The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, No. 12 Zhong-guan-cun South Street, Beijing 100081, China.
The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, No. 12 Zhong-guan-cun South Street, Beijing 100081, China.
Biochem Biophys Res Commun. 2015 Feb 20;457(4):627-34. doi: 10.1016/j.bbrc.2015.01.038. Epub 2015 Jan 19.
In this study, a necrosis-inducing protein was purified from the culture filtrate of the necrotrophic fungus Botrytis cinerea BC-98 strain. Secreted proteins were collected and fractionated by liquid chromatography. The fraction with the highest necrosis-inducing activity was further purified. A glycoprotein named BcGs1 was identified by 2D electrophoresis and mass spectrometry. The BcGs1 protein consisted of 672 amino acids with a theoretical molecular weight of 70.487 kDa. Functional domain analysis indicated that BcGs1 was a glucan 1,4-alpha-glucosidase, a cell wall-degrading enzyme, with a Glyco_hydro_15 domain and a CBM20_glucoamylase domain. The BcGs1 protein caused necrotic lesions that mimicked a typical hypersensitive response and H2O2 production in tomato and tobacco leaves. BcGs1-treated plants exhibited resistance to B. cinerea, Pseudomonas syringae pv. tomato DC3000 and tobacco mosaic virus in systemic leaves. In addition, BcGs1 triggered elevation of the transcript levels of the defence-related genes PR-1a, TPK1b and Prosystemin. This is the first report of a Botrytis glucan 1,4-alpha-glucosidase triggering host plant immunity as an elicitor. These results lay a foundation for further study of the comprehensive interaction between plants and necrotrophic fungi.
在本研究中，从坏死营养型真菌灰葡萄孢BC-98菌株的培养滤液中纯化出一种坏死诱导蛋白。收集分泌蛋白并通过液相色谱进行分级分离。对具有最高坏死诱导活性的级分进一步纯化。通过二维电泳和质谱鉴定出一种名为BcGs1的糖蛋白。BcGs1蛋白由672个氨基酸组成，理论分子量为70.487 kDa。功能域分析表明，BcGs1是一种葡聚糖1,4-α-葡萄糖苷酶，一种细胞壁降解酶，具有Glyco_hydro_15结构域和CBM20_葡糖淀粉酶结构域。BcGs1蛋白在番茄和烟草叶片上引起了类似典型过敏反应和过氧化氢产生的坏死病变。经BcGs1处理的植物在系统叶中对灰葡萄孢、丁香假单胞菌番茄致病变种DC3000和烟草花叶病毒表现出抗性。此外，BcGs1触发了防御相关基因PR-1a、TPK1b和Prosystemin转录水平的升高。这是关于灰葡萄孢葡聚糖1,4-α-葡萄糖苷酶作为激发子触发宿主植物免疫的首次报道。这些结果为进一步研究植物与坏死营养型真菌之间的全面相互作用奠定了基础。
