Isolation And Purification Of Oligosaccharides From Fungal Cells And Exocrine Proteins And Study On Their Inducing Resistance In Plants

Oligosaccharides derived from fungus have the important effect on adjusting plant growth and plant resistant. So Oligosaccharides were used as biological pesticide widely, and the research of oligosaccharide biological pesticide is the most important subject in the field of biological control of plant diseases. In this paper, we prepared an elicitor from fungal DL1805 and researched the activity of the elicitors and the mechanism it worked.The experiment indicates that the DL1805 could grow well in the soybean culture medium, and the most suitable growth temperature is 25℃, low or high temperature will restricts the fungi's growth vigour, and the most suitable PH value is 6.8. The content of proteins of fermentation fluid research maximum after cultivate 4d.After the ion-exchange chromatography, we get three mixture including two saccharides portion and one protein portion. We did further research on the first mixture, and found that it contains three oligosaccharides by the method of mass spectrum. Analysis of Monosaccharide by High Performance Liquid Chromatography (HPLC) were performed, three monosaccharides were found : galactose : glucose : mannose=1: 12: 5 Green fluorescence can be found under the fluorescence microscope indicated that the oligosaccharide of DL1805 can induce the NO and H₂O₂; The oligosaccharide has effect on improving resistant of Nicotiana tabacum var to tobacco mosaic virus(TMV), and it also has the effect on restraining opening of vicia faba L's stomata and promoting growth of soybean.The fermentation fluid and proteins obtain from fermentation liquid both have the effects on promoting phytoalexin of soybean and improving resistant of Nicotiana tabacum var to TMV.