Journal of Integrative Agriculture ›› 2016, Vol. 15 ›› Issue (4): 812-821.DOI: 10.1016/S2095-3119(15)61176-5

• 论文 • 上一篇    下一篇

Functional identification of phenazine biosynthesis genes in plant pathogenic bacteria Pseudomonas syringae pv. tomato and Xanthomonas oryzae pv. oryzae

LI Wen1, XU You-ping2, Jean-Pierre Munyampundu1, XU Xin1, QI Xian-fei1, GU Yuan1, CAI Xin-zhong1, 3   

  1. 1 Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, P.R.China
    2 Center of Analysis and Measurement, Zhejiang University, Hangzhou 310058, P.R.China
    3 State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou 310058, P.R.China
  • 收稿日期:2015-06-02 出版日期:2016-04-01 发布日期:2016-04-07
  • 通讯作者: CAI Xin-zhong, Tel/Fax: +86-571-88982936, E-mail: xzhcai@zju.edu.cn
  • 作者简介:LI Wen, E-mail: liwen547249317@126.com
  • 基金资助:

    This work was financially supported by the grants from the Genetically Modified Organisms Breeding Major Projects, China (2014ZX0800905B), the Fundamental Research Funds for the Central Universities, China, and the Program for New Century 151 Talents of Zhejiang Province, China.

Functional identification of phenazine biosynthesis genes in plant pathogenic bacteria Pseudomonas syringae pv. tomato and Xanthomonas oryzae pv. oryzae

LI Wen1, XU You-ping2, Jean-Pierre Munyampundu1, XU Xin1, QI Xian-fei1, GU Yuan1, CAI Xin-zhong1, 3   

  1. 1 Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, P.R.China
    2 Center of Analysis and Measurement, Zhejiang University, Hangzhou 310058, P.R.China
    3 State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou 310058, P.R.China
  • Received:2015-06-02 Online:2016-04-01 Published:2016-04-07
  • Contact: CAI Xin-zhong, Tel/Fax: +86-571-88982936, E-mail: xzhcai@zju.edu.cn
  • About author:LI Wen, E-mail: liwen547249317@126.com
  • Supported by:

    This work was financially supported by the grants from the Genetically Modified Organisms Breeding Major Projects, China (2014ZX0800905B), the Fundamental Research Funds for the Central Universities, China, and the Program for New Century 151 Talents of Zhejiang Province, China.

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摘要： Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis (phz) genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato (Pst) DC3000 and Xanthomonas oryzae pv. oryzae (Xoo) PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-1-carboxylic acid (PCA) of Pst DC3000 accumulated to 13.4 μg L–1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL–1 PCA, while Xoo PXO99A was sensitive to 50 μg mL–1 PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.

Abstract: Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis (phz) genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato (Pst) DC3000 and Xanthomonas oryzae pv. oryzae (Xoo) PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-1-carboxylic acid (PCA) of Pst DC3000 accumulated to 13.4 μg L–1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL–1 PCA, while Xoo PXO99A was sensitive to 50 μg mL–1 PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.

Key words: pathogenicity , phenazine biosynthesis genes , phenazine-1-carboxylic acid , plant pathogenic bacteria , Pseudomonas syringae pv. tomato , Xanthomonas oryzae pv. oryzae