Arsenic is highly toxic element to all forms of life and is a major environmental contaminant. Understanding acquisition, detoxification and adaptation mechanisms in bacteria that are associated with the host in arsenic-rich conditions can provide novel insights into the evolutionary dynamics of host–microbe–environment interactions. In the present study, we have investigated an arsenic-resistance mechanism acquired during the evolution of a particular lineage in the population of   Xanthomonas oryzae   pv. oryzae, which is a serious plant pathogen infecting rice. Our study revealed the horizontal acquisition of a novel chromosomal 12 kb ars cassette in   X. oryzae   pv. oryzae IXO1088 that confers high resistance to arsenate/arsenite. The ars cassette comprises several genes that constitute an operon induced in the presence of arsenate/arsenite. Transfer of the cloned ars cassette to   X. oryzae   pv. oryzae BXO512, which lacks the cassette, confers an arsenic-resistance phenotype. Furthermore, the transcriptional response of   X. oryzae   pv. oryzae IXO1088 under arsenate/arsenite exposure was analysed using RNA sequencing. Arsenic detoxification and efflux, oxidative stress, iron acquisition/storage, and damage repair are the main cellular responses to arsenic exposure. Our investigation has provided insights into the existence of a novel detoxification and adaptation mechanism within the   X. oryzae   pv. oryzae population to deal with high-arsenic conditions outside the rice plant.

中文翻译：

---

辨别功能性抗砷盒在水稻病原体进化和适应中的作用

砷是对所有生命形式的剧毒元素，是一种主要的环境污染物。了解在富含砷的条件下与宿主相关的细菌的获取、解毒和适应机制，可以为宿主-微生物-环境相互作用的进化动力学提供新的见解。 在本研究中，我们研究了在稻黄单胞菌 pv种群中特定谱系进化过程中获得的抗砷机制。oryzae，它是一种严重的植物病原菌感染水稻。我们的研究揭示了在 X. oryzae  pv中水平采集了一个新的染色体 12 kb ars盒。稻米    IXO1088 对砷酸盐/亚砷酸盐具有高抗性。ars盒包含几个基因，这些基因构成在砷酸盐/亚砷酸盐存在下诱导的操纵子。将克隆的ars盒转移到 X. oryzae  pv。缺乏该盒的oryzae BXO512 具有抗砷表型。此外， X. oryzae  pv. 的转录反应。稻米    使用 RNA 测序分析砷酸盐/亚砷酸盐暴露下的 IXO1088。砷的解毒和外排、氧化应激、铁的获取/储存和损伤修复是对砷暴露的主要细胞反应。 我们的调查提供了对稻瘟病菌 内新的解毒和适应机制存在的见解。稻草种群以应对水稻植株外的高砷条件。