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 pathogen Fusarium sambucinum, and their effects on infection of Zanthoxylum bungeanum stems 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 host Z. 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 pathogen F. sambucinum and host plant Z. bungeanum.
Highlights
Plants are exposed to numerous microorganisms, but they are resistant to many potential pathogens because of their constitutive or inducible resistance [1]
Chitosan and oligochitosan were prepared from pathogen F. sambucinum, and their effects on infection of Z. bungeanum stems were investigated
Oligochitosan DP5 was purified from the DP5–6 fraction, and it was characterized structurally using ESI-MS, Fourier transform near-infrared spectrometer (FT-IR) spectroscopy, and NMR spectroscopy
Summary
Plants are exposed to numerous microorganisms, but they are resistant to many potential pathogens because of their constitutive or inducible resistance [1]. Inducible defense responses include plant cell wall reinforcement by the deposition of lignin, necrotic hypersensitive response, biosynthesis of phytoalexins and pathogenesis-related proteins, and enhancement of the activities of defensive enzymes, such as phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), chitinase (CHI) and glucanase [2,3,4]. The inducible resistance of a plant often accompanies infection with a pathogen or stimulation by elicitors [5,6]. Extensive research over the past several years has shown that elicitors from pathogens can trigger defense reactions in host plants. One well-described elicitor from a pathogen that induces the biosynthesis of phytoalexin is a glucan heptasaccharide from the cell walls of Phytophthora sojae in soybeans [7]. Many different types of elicitors from pathogens and non-pathogens have been shown to possess components that promote active disease resistance in plants [10,11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
