The Symbiosis Between Endophytic Fungi From Wild Rice And Arabidopsis Thaliana

Endophytic fungi have rich diversity in biological function. Scientists have paid many attentions to this area in recent years. Dark septate endophytic fungi (DSE), a major group of fungal endophytes colonized in roots, plays an important role in plant antibiotics and abiotic stress. The strains in this study originated from wild rice (Oryza granulata), which distributed in Xishuangbanna, Yunnan province, southwest of China. There is potential to find novel species of endophytic fungi with growth promotion, disease resistance and stress resistance due to special growing environment and encosystem. Exploring resources of endophytic fungi have important significance to maintain the balance of agriculture ecology and protect natural environment.1) A co-culture system between Arabidopsis thaliana and endophytic fungi was set up in1/2MS medium. After10-14days co-culture, growth of plant was observed. A strain with signicant promotion effect to Arabidopsis thaliana was screened.2) Harpophora oryzae is a endophytic fungus colonized in roots. The fungus showed apparent promoting effect on Arabidopsis thaliana. Biomass of A. thaliana inoculated with H.oryzae increased significantly when compared to control. The root hair is dense than the control. The root length is longer than the control but without significant. It showed that growth promotion of A. thaliana by the fungus maybe related to root nutrients absorbtion. Leaves of A. thaliana colonized with H.oryzae green the content of chlorophyll and chlorophyll a increased significantly, thus promote photosynthesis of A. thaliana and benefit to accumulation of organic compounds. The fungus enhanced disease resistance of A. thaliana to Botrytis cinerea in a certain extent.3) Transformants of Harpophora oryzae marked with fluorescence was co-cultivated with Arabidopsis, the pattern and dynamic in root colonization was observed under fluorescence microscope. The results showed that most of fungi colonized in epidermal cells of plant roots. 4) Effect of A.thaliana metabobism colonized by H.oryzae was analysed. Metabolites of A.thaliana leaves were determined by GC-MS and ion chromatogram. The results showed that most primary metabolites increased, nitrate decreased and chloride increased as well.