Centro de Citricultura Sylvio Moreira/Instituto Agronômico, Cordeirópolis, São Paulo, Brazil.
Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, Florida, USA.
J Bacteriol. 2019 Sep 20;201(20). doi: 10.1128/JB.00796-18. Print 2019 Oct 15.
subsp. causes citrus canker disease worldwide in most commercial varieties of citrus. Its transmission occurs mainly by wind-driven rain. Once reaches a leaf, it can epiphytically survive by forming a biofilm, which enhances the persistence of the bacteria under different environmental stresses and plays an important role in the early stages of host infection. Therefore, the study of genes involved in biofilm formation has been an important step toward understanding the bacterial strategy for survival in and infection of host plants. In this work, we show that the toxin-antitoxin (TA) system, which was previously identified only in human bacterial pathogens, is conserved in many spp. We further show that in , is involved in important processes, such as biofilm formation, exopolysaccharide (EPS) production, and motility. In addition, we show that plays a role in survival and virulence in host plants. Thus, this mechanism represents an important bacterial strategy for survival under stress conditions. Very little is known about TA systems in phytopathogenic bacteria. , in particular, has only been studied in bacterial human pathogens. Here, we showed that it is present in a wide range of sp. phytopathogens; moreover, this is the first work to investigate the functional role of this TA system in biology, suggesting an important new role in adaptation and survival with implications for bacterial pathogenicity.
subsp. 引起柑橘溃疡病在世界范围内的大多数商业品种的柑橘。其传播主要通过风雨驱动。一旦 到达叶片，它可以通过形成生物膜而在叶面上附生生存，这增强了细菌在不同环境胁迫下的持久性，并在宿主感染的早期阶段发挥重要作用。因此，研究与生物膜形成相关的基因一直是理解细菌在宿主植物中生存和感染策略的重要步骤。在这项工作中，我们表明，先前仅在人类细菌病原体中鉴定出的毒素-抗毒素 (TA) 系统在许多 spp 中保守。我们进一步表明，在 中， 参与生物膜形成、胞外多糖 (EPS) 产生和运动等重要过程。此外，我们表明 在宿主植物中的 存活和毒力中发挥作用。因此，这种机制代表了细菌在应激条件下生存的重要策略。关于植物病原细菌中的 TA 系统知之甚少。特别是，它仅在细菌人类病原体中进行了研究。在这里，我们表明它存在于广泛的 sp. 植物病原细菌中；此外，这是第一项研究该 TA 系统在 生物学中的功能作用的工作，表明它在适应和生存中具有重要的新作用，对细菌致病性有影响。
