Study Of Plant Endophytic Fungi GY1-1 In Rice Resistance Under Cd Stress

Cadmium（Cd） which is one of the most toxic trace pollutants in the world now. Cd could hinder plant growth when accumulating in plant. And rice, as one of food crop in the world, is seriously affected by Cd. So, alleviating the Cd stress becoming urgent.In this study, we used endophytic fungi GY1-1 which isolated from health Suaeda salsa leaves growing coastal saline-alkali soil to infect Liaoxing No.1. The experiment was divided into E+ and E-. 0, 50, 100 and 150 μM Cd supplemented with or without 5% fermentation broth respectively were added to the nutrient solution. Then we collected on shoot length, root length, dry weight of above-ground, dry weight of roots, collected data of photosynthetic and fluorescence（Chla, Chlb, Car, Pn, Fv/Fm, Fv/Fo）, ROS（O₂^-, H₂O₂）, MDA, electric conductivity, osmotic adjustment substances content（proline, soluble suger content, soluble protein content）, antioxidase enzyme（SOD, POD, CAT, GR, APX） and relevance antioxidant substance（GSH, GSSG, TASC, ASC, As A） in As A-GSH cycling, and Cd content in plant. Experiments were carried out to study the role of endophytic fungi GY1-1 in enhancing rice resistance under Cd stress. Results are as follows:1.Under all treatments, the shoot length, root length, dry weight of above-ground and dry weight of roots in E+ were higher than E-.2. Photosynthetic pigments, Pn, and fluorescence of E+ were higher than that in E-, which showed that the endophytic fungi GY1-1 can promote the photosynthesis of rice and increase the accumulation of organics.3. MDA content and electric conductivity in E+ were less than E-, membrane lipid peroxidation lower and less material extravasation in the cell in E+. Osmotic adjustment substances（soluble suger content, soluble pro content） in E+ were higher than that in E-; Proline in E+ was less than that in E-, which showed that the endophytic fungi GY1-1 could ameliorated the adverse effects of Cd stress. So, there was’ t extra synthesized proline..4. ROS in E+ were less than E-. The antioxidase enzyme activity in E+ were higher than E-.5. Antioxidase enzyme activity and TASC, ASC, As A content in As A-GSH cycling in E+ were higher than E-; GSH, GSSG content were less than E-.6. Cadmium content of roots in E+ was higher than E-. The Cd content of above-ground in E+ was less than E-, which showed that the endophytic fungi GY1-1 could stimulate the ability of roots for gathering Cd, change the distribution of Cd, and alleviated the harmful of Cd for above-ground of rice, and then promote the growth of rice plant.