›› 2020, Vol. 32 ›› Issue (11): 1994-2000.DOI: 10.3969/j.issn.1004-1524.2020.11.09

• Plant Protection • Previous Articles     Next Articles

Effects of three endophytic bacteria with the characteristic of controlling citrus canker on the activity of several defensive enzymes in navel orange

LAI Jiahao, SONG Shuilin, LIU Bing*   

  1. College of Agriculture, Jiangxi Agricultural University, Nanchang 330045, China
  • Received:2020-02-29 Online:2020-11-25 Published:2020-12-02

Abstract: The activity of the defense enzyme is an important index of the host defense response ability, and many biocontrol factors can cause the activity of the defense enzyme of the plant to be enhanced. In the previous work, three endophytic bacteria Bacillus sp. GN222, Kosakonia cowanii GN223 and Bacillus subtilis GN232 with control effect on citrus canker were selected. To clarify the control mechanism, the effects of three bacterial strains on the activities of several defensive enzymes in Newhall navel orange infected by Xanthomonas citri pv. citri were determined in this experiment. The results showed that three endophytic bacteria could induce and enhance the activity of defensive enzyme in navel orange trees which were infected by Xanthomonas citri pv. citri. The induction intensity of endophytic bacteria to polyphenol oxidase (PPO) and superoxide dismutase (SOD) was lower than that induced by Xanthomonas citri pv. citri, the enhancement effect of strain GN222 on catalase (CAT) was significantly stronger than that of other strains, the induction effect of strain GN223 on peroxidase (POD) was stronger than that of other strains, and the activity of SOD was weaker in all treatments. In a word, endophytic bacteria to be tested have a certain inducing effect on defensive enzymes in the process of navel orange infected by Xanthomonas citri pv. citri, but the time and range of enzyme activity increased variously with different bacterial strains. The results could provide a theoretical basis for the application of three endophytic bacteria in the biological control of citrus canker.

Key words: citrus canker, endophytic bacteria, defensive enzyme

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