Journal of Integrative Agriculture ›› 2012, Vol. 12 ›› Issue (4): 600-610.DOI: 10.1016/S1671-2927(00)8580

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Xoryp_08180 of Xanthomonas oryzae pv. oryzicola, Encoding a Hypothetical Protein, is Regulated by HrpG and HrpX and Required for Full Virulence in Rice

 SHEN Yi-ping, ZOU Li-fang, LI Yu-rong, ZOU Hua-song, LIU Xi-ling , CHEN Gong-you   

  1. 1.School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban (South), Ministry of Agriculture, Shanghai 200240, P.R.China
    2.Department of Plant Protection, Nanjing Agricultural University/Key Laboratory of Integrated Management of Crop Diseases and Pests,Ministry of Education, Nanjing 210095, P.R.China
  • 收稿日期:2011-04-15 出版日期:2012-04-01 发布日期:2012-04-11
  • 通讯作者: Correspondence CHEN Gong-you, Tel: +86-21-34205873, Fax: +86-21-34205873, E-mail: gyouchen@sjtu.edu.cn
  • 作者简介:SHEN Yi-ping, Tel: +86-21-34205873, E-mail: yipingshen.syp@gmail.com
  • 基金资助:

    This work was supported by the National Natural Science Foundation of China (31071656, 31000071), the National Transgenic Major Program, China (2008ZX08001-002) and the Special Fund for Agro-scientific Research in the Public Interest, China (NYHYZX07-056).

Xoryp_08180 of Xanthomonas oryzae pv. oryzicola, Encoding a Hypothetical Protein, is Regulated by HrpG and HrpX and Required for Full Virulence in Rice

 SHEN Yi-ping, ZOU Li-fang, LI Yu-rong, ZOU Hua-song, LIU Xi-ling , CHEN Gong-you   

  1. 1.School of Agriculture and Biology, Shanghai Jiao Tong University/Key Laboratory of Urban (South), Ministry of Agriculture, Shanghai 200240, P.R.China
    2.Department of Plant Protection, Nanjing Agricultural University/Key Laboratory of Integrated Management of Crop Diseases and Pests,Ministry of Education, Nanjing 210095, P.R.China
  • Received:2011-04-15 Online:2012-04-01 Published:2012-04-11
  • Contact: Correspondence CHEN Gong-you, Tel: +86-21-34205873, Fax: +86-21-34205873, E-mail: gyouchen@sjtu.edu.cn
  • About author:SHEN Yi-ping, Tel: +86-21-34205873, E-mail: yipingshen.syp@gmail.com
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (31071656, 31000071), the National Transgenic Major Program, China (2008ZX08001-002) and the Special Fund for Agro-scientific Research in the Public Interest, China (NYHYZX07-056).

摘要: Xanthomonas oryzae pv. oryzicola (Xoc) causes a destructive bacterial leaf streak disease in rice. Some of the gene products annotated as hypothetical proteins in the genome of Xoc may contribute to its virulence in rice. A mutant, Mxoc1679, screened from our previous Tn5-tagged mutant library for Xoc strain RS105, showed reduced virulence in rice. In this mutant, a gene named as Xoryp_08180 was disrupted by Tn5 insertion. Xoryp_08180 encodes a 1 306-aa hypothetical protein which is highly conserved in Xanthomonas spp. Non-polar mutation of Xoryp_08180 in RS105 strain led to a significant reduction in bacterial virulence and growth in rice, a delayed hypersensitive response (HR) in non-host tobacco, and a decrease in extracellular protease activity. The deficiencies above were restored to wild-type level in the complementary strain by expressing Xoryp_08180 in trans. In addition, the expression of Xoryp_08180 was repressed in hrpG and hrpX mutants in planta but not in a nutrient-rich condition. These results suggested that Xoryp_08180 is a virulence factor required for extracellular protease production, HR induction and full virulence of Xoc.

关键词: Xanthomonas oryzae pv. oryzicola, Xoryp_08180, hypothetical protein, virulence, hypersensitive response, extracellular protease

Abstract: Xanthomonas oryzae pv. oryzicola (Xoc) causes a destructive bacterial leaf streak disease in rice. Some of the gene products annotated as hypothetical proteins in the genome of Xoc may contribute to its virulence in rice. A mutant, Mxoc1679, screened from our previous Tn5-tagged mutant library for Xoc strain RS105, showed reduced virulence in rice. In this mutant, a gene named as Xoryp_08180 was disrupted by Tn5 insertion. Xoryp_08180 encodes a 1 306-aa hypothetical protein which is highly conserved in Xanthomonas spp. Non-polar mutation of Xoryp_08180 in RS105 strain led to a significant reduction in bacterial virulence and growth in rice, a delayed hypersensitive response (HR) in non-host tobacco, and a decrease in extracellular protease activity. The deficiencies above were restored to wild-type level in the complementary strain by expressing Xoryp_08180 in trans. In addition, the expression of Xoryp_08180 was repressed in hrpG and hrpX mutants in planta but not in a nutrient-rich condition. These results suggested that Xoryp_08180 is a virulence factor required for extracellular protease production, HR induction and full virulence of Xoc.

Key words: Xanthomonas oryzae pv. oryzicola, Xoryp_08180, hypothetical protein, virulence, hypersensitive response, extracellular protease