The Endophytic Fungi Induce Resistance Against Plant Pathogen In Pinus Massoniana

Endophytic fungi live within the plant tissue.The endophytes and the plant benefit each other.Research shows that endophytic fungi can enhance the resistance of the host plant to the biotic and nonbiotic stress,and promote the growth of host. Nowadays,more attention is paid to the interaction between endophytes and woody plants because of the potent economic value.In this study,endophytic fungi from Pinus massoniana were isolated and identified.We also studied the relationship between the endophytic fungi and the resistance of Pinus massoniana to pathogen Fusarium sp..Totally,303 fungal endophytes were obtained from symptom-free masson pine (Pinus massoniana) from five different localities:Xianyue Hill,Huwei Hill and Xiang'an Farm in Xiamen,Dahuyu town and Yuanyu town in Shandong Province. 215 isolates were identified by morphological and molecular methods.The most frequently found endophytic fungi were Phomopsis sp.(46.51%).Aspergillus sp.were followed(17.67%).The fungi isolated were included in 23 genera,distributing in 3 phyla(Ascomycotina,Basidiomycotina and Zygomycotina).In order to inoculate axenically and prevent hosts from contamination,an axenic system of "double-tubes" was set up.Also,different methods were compared to find an optimum way for disinfecting the seeds and the surface of the seedlings.31 isolates were evaluated in vivo by their ability to inhibit Fusarium sp..8 isolates exhibited high rates of reisolation(more than or equal to 50%).The rDNA sequences of these 8 fungi and their reisolates were aligned to elucidate the homology, respectively.It shows that they are exactly the enhophytes.Hyphae were stained and detected under the microscopes for some isolates.8 isolates(HG09,XY20(2),XY30,TJ16,HG17,HZ08,TZ16 and HZ40) were choosen for the further research.They are evaluated in vivo by their ability to enhance the activities of peroxidase and polyphynol oxidase of the masson pine.3 fungi were selected for a secondary experiment.Proteins were extracted from the axenic plant,pathogen P7-plant,endophyte XY30-plant and pathogen- XY30-plant.Two dimensional electrophoresis was followed by silver staining.Proteins relative to phytosynthesis,growth and protein synthesis were found.In conclusion,under the strict experiment condition,we found that there were abundance of endophytic fungi living within the masson pine tissue.XY30 can enhance the resisitance of masson pine to pathogen Fusarium sp.