Proteins Extraction From Bamyard Grass Pathogenic Fungus Curvularia Lunata And Their Induced Rice Resistance To Rice Blast

The active substances of Curvularia lunata (CL) which is the pathogenic fungus isolated from infected leaves of bamyardgrass (Echinochloa spp.) could induced resistance to rice blast. This dissertation presented the abstraction and purification of the active substances and their function of induction resistance to rice blast.The results were showed as follows:The thallus of CL fungus was grinded to powder by liquid nitrogen grinding method, and the powder was dissolved by 30mmol/L pH8.0 Tris-HCL buffer in the ratio of 1:4 (W/V) under the temperature of 4℃. After high speed freezing centrifugation, the supernatant was precipitated by 40%-60% ammonium sulfate. Later, the mixture was carefully transferred to 50 mL eppendorf tube, and centrifuged at 13 000 rpm for 20 min to obtain the precipitation. It was dissolved by the same buffer and then dialysed in sterile water, and the product was the active substances (AS) of CL fungus. According to the result of SDS-PAGE, it was known that the molecular weight of AS was between 12kD-80kD.The active substances of CL fungus could promote the rice growth. The plants height and their dry weight treated with active substances of CL were significantly increased than that of the contro.The enzyme activity related with rice growth ,shuch as succinate dehydrogenase (SDH), increased in the leave of treating with treated with active substances of CL .The active substances of CL could induce resistance to blast in rice. The control efficiency of the rice treated with 13.6μg/mL of active substances of CL to rice blast was 38.66%. The activity of resistance-related enzymes,such as phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were higher than that of control.In field tests, the chlorophyll content and photosynthetic rate increased after treating with active substances of CL. The rice yield increased 3.95%, 7.14% and 8.40% in Zhongjian99-38 ,Zhongzao25 and Xuishui cultivates of rice, respectively. The active substances of CL could induce resistance to blast in field tests. The control efficiency of the rice treated with active substances of CL to rice blast was 42.90%. The activity of resistance-related enzymes, such as peroxidase (POD), were higher than that of control.