title: Structural Characterization of Oligochitosan Elicitor from Fusarium sambucinum and Its Elicitation of Defensive Responses in Zanthoxylum bungeanum.
abstract: Oligosaccharide elicitors from pathogens have been shown to play major roles in host plant defense responses involving plant-pathogen chemoperception and interaction. In the present study, chitosan and oligochitosan were prepared from pathogenFusarium sambucinum, and their effects on infection ofZanthoxylum bungeanumstems were investigated. Results showed that oligochitosan inhibited the infection of the pathogen, and that the oligochitosan fraction with a degree of polymerization (DP) between 5 and 6 showed the optimal effect. Oligochitosan DP5 was purified from fraction DP5-6 and was structurally characterized using electrospray ionization mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. Oligochitosan DP5 showed significant inhibition against the infection of the pathogenic fungi on host plant stems. An investigation of the mechanism underlying this effect showed that oligochitosan DP5 increased the activities of defensive enzymes and accumulation of phenolics in hostZ. bungeanum. These results suggest that oligochitosan from pathogenic fungi can mediate the infection of host plants with a pathogen by acting as an elicitor that triggers the defense system of a plant. This information will be valuable for further exploration of the interactions between the pathogenF. sambucinumand host plantZ. bungeanum.
authors.affiliation: Department of Forest Pathology, College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China. lipq@nwsuaf.edu.cn.
authors.forename: Peiqin
authors.initials: P
authors.lastname: Li
authors.affiliation: Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. linhar@rpi.edu.|Department of Chemistry and Chemical Biology, Chemical and Biological Engineering, and Biology and Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. linhar@rpi.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Linhardt
authors.affiliation: Department of Forest Pathology, College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China. zmcao@nwsuaf.edu.cn.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Cao
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D048271:Chitosan / Q000302:isolation & purification / Q000494:pharmacology; D005670:Fusarium / Q000737:chemistry*; D009844:Oligosaccharides; D010636:Phenols / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D018547:Plant Stems / Q000187:drug effects / Q000382:microbiology; D066244:Proton Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D032106:Zanthoxylum / Q000187:drug effects / Q000201:enzymology / Q000276:immunology* / Q000382:microbiology*
chemical_list: D009844:Oligosaccharides; D010636:Phenols; C493484:oligochitosan; D002686:Chitin; D048271:Chitosan
keywords: Fusarium sambucinum; Zanthoxylum bungeanum; defensive response; fungal oligochitosan elicitor; plant–pathogen interaction; structural characterization