Structure-dependent modulation of a pathogen response in plants by synthetic O-antigen polysaccharides
Structure-dependent modulation of a pathogen response in plants by synthetic O-antigen polysaccharides
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DOI：
10.1021/ja0452166
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发表时间：
2005-03-02
影响因子：
15
通讯作者：
Unverzagt, C
中科院分区：
文献类型：
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作者：
Bedini, E;De Castro, C;Unverzagt, C
许多植物病原性细菌显示具有O-链重复单元[α-L-Rha-（1->3）-α-L-Rha-（1-> 3）-α-L-Rha-（1->2）]（n）的脂多糖（LIPS）。该三糖单元被合成并低聚以获得六糖和九糖。脱保护的鼠李聚糖在抑制拟南芥过敏反应（HR）和诱导PR-1基因表达方面是有效的。通过NMR光谱和分子动力学计算的寡聚鼠李糖的构象分析表明，随着寡糖链长的增加，卷曲结构发展。这与HR抑制和PR-1基因表达的有效性增加有关。因此，我们推断植物病原细菌的卷曲结构是一种植物可识别的病原相关分子模式（PAMP）。
Many phytopathogenic bacteria display lipopolysaccharides (LIPS) with the O-chain repeating unit [alpha-L-Rha-(1-->3)-alpha-L-Rha-(1-->3)-alpha-L-Rha-(1-->2)](n). This trisaccharide unit was synthesized and oligomerized to obtain hexa- and nonasaccharides. The deprotected rhamnans were effective in suppressing the hypersensitive response (HR) and in inducing PR-1 gene expression in Arabidopsis thaliana. Conformational analysis of the oligorhamnans by NMR spectroscopy and molecular dynamics calculations revealed that a coiled structure develops with increasing chain length of the oligosaccharide. This is associated with increasing efficacy in HR suppression and PR-1 gene expression. We therefore infer that the coiled structure of phytopathogenic bacteria is a plant-recognizable pathogen-associated molecular pattern (PAMP).