研究组报道了糖苷的结构、生物合成和多功能作用。高分辨率低温电子显微镜和化学合成表明，糖苷是一种具有五元吡啶环和水合醛的亚糖，模拟单糖。糖苷的生物合成受毒力调节因子控制，其在细菌中普遍产生，阻止鞭毛蛋白识别并改变受感染植物的细胞外糖蛋白组和代谢组。这些发现强调了植物病原体在整个植物界对糖生物学操纵的潜在更广泛的作用。
据了解，植物的胞外空间（外质体）是微生物感染的关键战场。为避免被识别，本文将细菌模式植物病原体丁香假单胞菌pv。番茄DC3000产生糖苷。糖苷抑制植物分泌的β-半乳糖苷酶BGAL1，否则会启动细菌鞭毛蛋白释放免疫原性肽。
附：英文原文
Title: Bacterial pathogen deploys the iminosugar glycosyrin to manipulate plant glycobiology
Author: Nattapong Sanguankiattichai, Balakumaran Chandrasekar, Yuewen Sheng, Nathan Hardenbrook, Werner W. A. Tabak, Margit Drapal, Farnusch Kaschani, Clemens Grünwald-Gruber, Daniel Krahn, Pierre Buscaill, Suzuka Yamamoto, Atsushi Kato, Robert Nash, George Fleet, Richard Strasser, Paul D. Fraser, Markus Kaiser, Peijun Zhang, Gail M. Preston, Renier A. L. van der Hoorn
Issue&Volume: 2025-04-18
Abstract: The extracellular space (apoplast) in plants is a key battleground during microbial infections. To avoid recognition, the bacterial model phytopathogen Pseudomonas syringae pv. tomato DC3000 produces glycosyrin. Glycosyrin inhibits the plant-secreted β-galactosidase BGAL1, which would otherwise initiate the release of immunogenic peptides from bacterial flagellin. Here, we report the structure, biosynthesis, and multifunctional roles of glycosyrin. High-resolution cryo–electron microscopy and chemical synthesis revealed that glycosyrin is an iminosugar with a five-membered pyrrolidine ring and a hydrated aldehyde that mimics monosaccharides. Glycosyrin biosynthesis was controlled by virulence regulators, and its production is common in bacteria and prevents flagellin recognition and alters the extracellular glycoproteome and metabolome of infected plants. These findings highlight a potentially wider role for glycobiology manipulation by plant pathogens across the plant kingdom.
DOI: adp2433
Source: https://www.science.org/doi/10.1126/science.adp2433