Structure-Dependent Modulation of a Pathogen Response in Plants by Synthetic O-Antigen Polysaccharides
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- 作者：Emiliano Bedini ; Cristina De Castro ; Gitte Erbs ; Lorenzo Mangoni ; J. Maxwell Dow ; Mari-Anne Newman ; Michelangelo Parrilli ; and Carlo Unverzagt
- 刊名：Journal of the American Chemical Society
- 出版年：2005
- 出版时间：March 2, 2005
- 年：2005
- 卷：127
- 期：8
- 页码：2414 - 2416
- 全文大小：137K
- 年卷期：v.127,no.8(March 2, 2005)
- ISSN：1520-5126
文摘
Many phytopathogenic bacteria display lipopolysaccharides (LPS) with the O-chain repeatingunit [
-L-Rha-(1
3)--L-Rha-(13)--L-Rha-(12)]n. This trisaccharide unit was synthesized and oligomerized to obtain hexa- and nonasaccharides. The deprotected rhamnans were effective in suppressingthe hypersensitive response (HR) and in inducing PR-1 gene expression in Arabidopsis thaliana.Conformational analysis of the oligorhamnans by NMR spectroscopy and molecular dynamics calculationsrevealed that a coiled structure develops with increasing chain length of the oligosaccharide. This isassociated with increasing efficacy in HR suppression and PR-1 gene expression. We therefore infer thatthe coiled structure of phytopathogenic bacteria is a plant-recognizable pathogen-associated molecularpattern (PAMP).
-L-Rha-(13)--L-Rha-(13)--L-Rha-(12)]n. This trisaccharide unit was synthesized and oligomerized to obtain hexa- and nonasaccharides. The deprotected rhamnans were effective in suppressingthe hypersensitive response (HR) and in inducing PR-1 gene expression in Arabidopsis thaliana.Conformational analysis of the oligorhamnans by NMR spectroscopy and molecular dynamics calculationsrevealed that a coiled structure develops with increasing chain length of the oligosaccharide. This isassociated with increasing efficacy in HR suppression and PR-1 gene expression. We therefore infer thatthe coiled structure of phytopathogenic bacteria is a plant-recognizable pathogen-associated molecularpattern (PAMP).