Phage Resistance Reduced the Pathogenicity of <i>Xanthomonas oryzae</i> pv. <i>oryzae</i> on Rice
Mengju Liu,
Ye Tian,
Haitham E. M. Zaki,
Temoor Ahmed,
Rong Yao,
Chengqi Yan,
Sebastian Leptihn,
Belinda Loh,
Muhammad Shafiq Shahid,
Fang Wang,
Jianping Chen,
Bin Li
Affiliations
Mengju Liu
State Key Laboratory of Rice Biology, and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, and Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
Ye Tian
State Key Laboratory of Rice Biology, and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, and Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
Haitham E. M. Zaki
Horticulture Department, Faculty of Agriculture, Minia University, El-Minia 61517, Egypt
Temoor Ahmed
State Key Laboratory of Rice Biology, and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, and Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
Rong Yao
State Key Laboratory of Rice Biology, and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, and Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
Chengqi Yan
Institute of Biotechnology, Ningbo Academy of Agricultural Sciences, Ningbo 315040, China
Sebastian Leptihn
University of Edinburgh Institute, Zhejiang University, Hangzhou 314400, China
Belinda Loh
Fraunhofer Institute for Cell Therapy & Immunology (IZI), Department of Vaccines and Infection Models, Perlickstr. 1, 04103 Leipzig, Germany
Muhammad Shafiq Shahid
Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al-khod 123, Oman
Fang Wang
Institute of Biotechnology, Ningbo Academy of Agricultural Sciences, Ningbo 315040, China
Jianping Chen
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo 315211, China
Bin Li
State Key Laboratory of Rice Biology, and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, and Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
Plants grow together with microbes that have both negative and positive impacts on the host, while prokaryotes are in turn also hosts for viruses, co-evolving together in a complex interrelationship. Most research focuses on the interaction of either bacterial pathogens interacting with the plant host, or the impact on viruses on their pathogenic bacterial hosts. Few studies have investigated the co-evolution of bacterial pathogens with their host plants as well as with their bacterial viruses. In this work, we aimed to identify the genes that were associated with both phage sensitivity and host pathogenicity of the bacterium Xanthomonas oryzae pv. oryzae (Xoo), which is the most important bacterial rice pathogen. Using the Tn5 transposon mutation technology, we created a library of Xoo strain C2 comprising 4524 mutants, which were subsequently tested for phage infectability. The phage infection tests showed that less than 1% of the mutants (n = 36) were resistant to phage infection, which was attributed to the Tn5 insertion in 19 genes. Interestingly, three out of 19 genes that conveyed resistance to the phage resulted in reduced pathogenicity to rice seedlings compared to the wild type. We identified three genes involved in both phage infection and bacterial virulence, which were studied by knockout mutants and complementation experiments. All of the three knockout mutants were resistant to infection by phage X2, while the complemented strains restored the susceptibility to the bacterial virus. Surprisingly, the genes are also essential for pathogenicity, which we confirmed by single knockout mutants corresponding to the Tn5 mutants. All three genes are involved in lipopolysaccharide synthesis, thus changing the cell envelope surface molecule composition. Our work shows a possible balance in terms of the connection between bacterial virulence and phage resistance, supporting the deployment of phages for the biocontrol of plant pathogens.
