title: CatB is Critical for Total Catalase Activity and Reduces Bactericidal Effects of Phenazine-1-Carboxylic Acid on Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola.
abstract: Rice bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, and rice bacterial leaf streak, caused by X. oryzae pv. oryzicola, are major diseases of rice. Phenazine-1-carboxylic acid (PCA) is a natural product that is isolated from Pseudomonas spp. and is used to control many important rice diseases in China. We previously reported that PCA disturbs the redox balance, which results in the accumulation of reactive oxygen species in X. oryzae pv. oryzae. In this study, we found that PCA significantly upregulated the transcript levels of catB and katE, which encode catalases, and that PCA sensitivity was reduced when X. oryzae pvs. oryzae and oryzicola were cultured with exogenous catalase. Furthermore, catB deletion mutants of X. oryzae pvs. oryzae and oryzicola showed dramatically decreased total catalase activity, increased sensitivity to PCA, and reduced virulence in rice. In contrast, deletion mutants of srpA and katG, which also encode catalases, exhibited little change in PCA sensitivity. The results indicate that catB in both X. oryzae pvs. oryzae and oryzicola encodes a catalase that helps protect the bacteria against PCA-induced stress.
authors.affiliation: College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xiayan
authors.initials: X
authors.lastname: Pan
authors.affiliation: College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wu
authors.affiliation: College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Xu
authors.affiliation: College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yabing
authors.initials: Y
authors.lastname: Duan
authors.affiliation: College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Mingguo
authors.initials: M
authors.lastname: Zhou
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D002681:China; D012275:Oryza / Q000382:microbiology*; D010619:Phenazines / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D014774:Virulence; D014974:Xanthomonas / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity
chemical_list: D000900:Anti-Bacterial Agents; D010619:Phenazines; C037165:1-phenazinecarboxylic acid; D002374:Catalase
keywords: total catalase activities