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Chinese Journal Of Biological Control ›› 2020, Vol. 36 ›› Issue (2): 211-219.DOI: 10.16409/j.cnki.2095-039x.2020.02.006

• RESEARCH REPORTS • Previous Articles     Next Articles

Physical and Chemical Properties and Inhibitory Effect of Crude Antifungal Protein Produced by Bacillus tequilensis JN-369

ZHOU Hu1,2,3, HU Ling1, YU Xiyue1, ZHU Huajun1,2,3, REN Zuohua1,2, LIU Erming1,2,3   

  1. 1. College of Plant Protection, Hunan Agricultural University, Changsha 410128, China;
    2. Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Changsha 410128, China;
    3. Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha 410128, China
  • Received:2019-05-25 Online:2020-04-08 Published:2020-04-16

Abstract: Bacillus tequilensis strain JN-369 is a biocontrol strain with antagonism on Magnaporthe oryzae. The antifungal protein crude extraction was precipitated by ammonium sulphate after fermentation. To determine the antifungal mechanism of the crude protein the inhibition spectrum, thermostability, acid-base stability, UV stability and enzyme stability were investigated, the inhibition effect to M. oryzae hyphae and spores was observed, and the antagonistic effects of 40% Isoprothiolane EC, 25% Tricyclazole WP and the crude antifungal protein against M. oryzae in rice were detected by tissue inoculation in vitro. Results indicated that the crude antifungal protein of the strain JN-369 had a broad inhibition spectrum, with inhibition activity on 13 plant pathogenic fungi and oomycetes, such as B. cinerea, M. oryzae, but no inhibition on S. sclerotiorum. The crude proteinstill had antifungal activity after heat treatment, pH treatment, UV treatment and enzyme treatment, indicating it has potential application value in biocontrol of food crops. After treatment with crude protein, M. oryzae hyphae became enlargement and could inhibit conidiospores germination. The in vitro efficacy experiments showed that all treatments had significant antagonistic effects on rice blast, and the crude antifungal protein at 50 ug/mL to 100 ug/mL had the best antagonistic effect on rice blast.The strain JN-369 was expected to be developed as a Biocontrol Strain for the control of rice blast.

Key words: Magnaporthe oryzae, Bacillus tequilensis, crude antifungal protein, biocontrol

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