链霉菌糖蛋白GP-1诱导植物抗病性的分子靶标研究

糖蛋白GP-1是分离自链霉菌ZX01代谢产物中的一种新型糖蛋白，该糖蛋白对TMV具有显著抑制作用。申请者在青年自然科学基金（31201536）资助下，发现GP-1能诱导烟草防御体系早期信号产生，激活水杨酸相关信号通路，以及诱导多种防御相关基因的表达，表明GP-1能诱导植物产生免疫抗性，具有植物诱导子特征。进一步采用FITC荧光标记法证明GP-1可定位于烟草细胞表面，推测细胞表面存在与GP-1识别、结合的受体蛋白。本项目拟在此基础上，利用酵母双杂交技术筛选糖蛋白GP-1在烟草中的互作蛋白，通过体内、体外蛋白互作进行验证，并对筛选到的互作蛋白进行蛋白质表达、生物学功能分析，同时进一步采用微量热泳动分析、同源建模、分子对接等技术对GP-1的靶标蛋白进行确证。研究结果将为糖蛋白GP-1诱导植物免疫抗性机制提供直接证据，为植物免疫诱抗剂的创制提供科学依据。

The GP-1, a novel glycoprotein with the activity of inducing system resistance in plant, was isolated from the metabolites of Streptomyces kanasensis ZX01 and showed a great activity against TMV. Our preliminary works, was funded by the National Natural Science Foundation of China Youth Fund (No. 31201536), have demonstrated that GP-1 induces hypersensitive response (HR), and stimulates the early signal events of defense systems. The expression of defense-related genes and salicylic acid (SA) signal pathways were activated by treating with GP-1. In summary, the results indicated that GP-1 was a plant elicitor. The suspension cell of tobacco, treated with FITC labeled GP-1, showed a fluorescence. Therefore, we plan to (1) screen the interacting proteins in tobacco K326 treated with GP-1 by yeast two-hybrid technology, (2) verify the interacting proteins by bioinformatics analysis and eukaryotic expression, (3) confirm the targets protein of GP-1 by microscale thermophoresis, homology modeling and molecular docking simulation. This research will elucidate the mode of action of GP-1 and provide scientific basis for the development of the plant elicitors.