Abstract:In order to investigate the effect of Streptomyces JD211 on physiological mechanism of hypersensitive response in rice after inoculation with Magnaporthe grisea, with the rice variety “Luliangyou 996” as materials, we conducted pot experiments by applying powdered Streptomyces JD211 cultivation of rice and inoculated with rice blast fungus spore suspension, and then sprayed with water as control, hydrogen peroxide (H2O2), catalase (CAT), lipoxygenase (LOX), malondialdehyde (MDA) and cell membrane permeability in rice leaves were determined. The results showed that: (1) when the rice seedling age was 30 days, the treatment group with adding Streptomyces JD211, (CAT), (LOX) and (H2O2) increased by 50.30%, 40.85% and 45.31%, respectively compared with the control group and (MDA) decreased by 25.75%. (2) After inoculate with Magnaporthe grisea, plus JD211 treatment group, (CAT), (LOX) and (H2O2) were increased by 33.50%, 4.07% and 47.76% than that of the group without JD211, MDA decreased by 38.68%. (3) After inoculation of Magnaporthe grisea, the JD211 treatment group compared to the group without JD211, cell membrane permeability increased by 38.94%, 39.03% and 8.08% at the age of 32 days, 34 days, 36 days, respectively. It is considered that Streptomyces JD211 enhanced the content of H2O2, and the activities of CAT and LOX, while inhibited the accumulation of MDA. The cell membrane permeability also increased with the inoculation of Magnaporthe grisea in the later stages, which can effectively regulate the hypersensitive response in the cell, induced cell necrosis, further prevented pathogens infection, and effectively improved rice resistance to rice blast.