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
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
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DOI：
10.1094/phyto-07-16-0251-r
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发表时间：
2017-02-01
期刊：
影响因子：
3.2
通讯作者：
Zhou, Mingguo
中科院分区：
文献类型：
--
作者：
Pan, Xiayan;Wu, Jian;Zhou, Mingguo
水稻白叶枯病是由水稻白叶枯病菌Xanthomonas oryzae pv.水稻细菌性条斑病是由X. oryzaepv.稻瘟病菌是水稻的主要病害。吩嗪-1-羧酸（PCA）是从假单胞菌属（Pseudomonas spp.）中分离得到的天然产物。并用于防治我国许多重要的水稻病害。我们以前报道过，PCA扰乱了氧化还原平衡，导致活性氧在X中积累。oryzaepv.米。在本研究中，我们发现PCA显著上调了编码过氧化氢酶的catB和katE的转录水平，并且当X.稻瘟病菌水稻和稻生菌与外源过氧化氢酶一起培养。此外，还获得了X.稻瘟病菌水稻和稻虱在水稻中表现出显著降低的总过氧化氢酶活性、增加的对PCA的敏感性和降低的毒性。相比之下，srpA和katG的缺失突变体（其也编码过氧化氢酶）在PCA敏感性方面表现出很小的变化。结果表明，catB在两个X.稻瘟病菌水稻和稻生菌编码一种有助于保护细菌免受PCA诱导的应激的过氧化氢酶。
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.