Insights into the roles of two genes of the histidine biosynthesis operon in pathogenicity of Xanthomonas oryzae pv. oryzicola
Insights into the roles of two genes of the histidine biosynthesis operon in pathogenicity of Xanthomonas oryzae pv. oryzicola
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深入了解组氨酸生物合成操纵子的两个基因在米黄单胞菌致病性中的作用。
DOI：
10.1094/phyto-09-17-0332-r
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发表时间：
--
期刊：
影响因子：
3.2
通讯作者：
Fengquan Liu
中科院分区：
文献类型：
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作者：
Panpan Su;Zhiwei Song;Guichun Wu;Yancun Zhao;Yuqiang Zhang;Bo Wang;Guoliang Qian;Zheng Qing Fu;Fengquan Liu
水稻黄单胞菌引起水稻细菌性条斑病的水稻致病变种。在这项研究中，我们进行了九基因hisoperon在X的功能特性。oryzaepv.oryzicola.序列分析表明该操纵子在黄单胞菌属中高度保守。营养分析证实组氨酸操纵子参与组氨酸的生物合成。我们发现，该操纵子中的两个基因，trpRandhisB，是植物中的毒性和细菌生长所必需的。进一步的研究表明trp RandhisB在X染色体上起着不同的作用。oryzaepv.oryzicola. trpR作为转录抑制因子，可以负调控hisG、-D、-C、-B、-H、-A和-F的表达。hisB编码一种与组氨酸生物合成有关的双功能酶，是X产生黄单胞菌素所必需的。oryzaepv.oryzicola. hisB的破坏降低了5个已知莽草酸途径相关基因xanB 2、aroE、aroA、aroC和aroK的转录表达。我们发现X. oryzaepv.oryzicolais不参与非寄主烟草的过敏反应。总的来说，我们的结果表明，组氨酸生物合成操纵子中的两个基因在X的致病性中发挥重要作用。oryzaepv.oryzicolaRs105.
Xanthomonas oryzaepv.oryzicolais anX. oryzaepathovar that causes bacterial leaf streak in rice. In this study, we performed functional characterization of a nine-genehisoperon inX. oryzaepv.oryzicola. Sequence analysis indicates that this operon is highly conserved inXanthomonasspp. Auxotrophic assays confirmed that thehisoperon was involved in histidine biosynthesis. We found that two genes within this operon,trpRandhisB, were required for virulence and bacterial growth in planta. Further research revealed thattrpRandhisBplay different roles inX. oryzaepv.oryzicola. ThetrpRacts as a transcriptional repressor and could negatively regulate the expression ofhisG, -D, -C, -B, -H, -A, and -F.hisB, which encodes a bifunctional enzyme implicated in histidine biosynthesis, was shown to be required for xanthomonadin production inX. oryzaepv.oryzicola. The disruption ofhisBreduced the transcriptional expression of five known shikimate pathway-related genesxanB2,aroE,aroA,aroC, andaroK. We found that thehisoperon inX. oryzaepv.oryzicolais not involved in hypersensitive response in nonhost tobacco plants. Collectively, our results revealed that two genes in histidine biosynthesis operon play an important role in the pathogenicity ofX. oryzaepv.oryzicolaRs105.