Zhang Bo, Zhang Yang, Liang Fei, Ma Yinan, Wu Xiaogang
College of Agriculture, Guangxi University, Nanning, China.
Department of Plant Pathology, China Agricultural University, Beijing, China.
Front Microbiol. 2019 Sep 11;10:2005. doi: 10.3389/fmicb.2019.02005. eCollection 2019.
The GacS/GacA two-component system is essential for virulence in many plant pathogenic bacteria, and thus represents a promising anti-virulence target. In the present study, we isolated and screened rhizobacteria that were capable of inhibiting the expression of the gene in the phytopathogenic bacterium pv. () DC3000. One candidate inhibitor bacterium, BR3 was obtained and identified as a sp. strain based on 16s rRNA gene sequence analysis. Besides the gene, the GacA-dependent small RNA genes and were repressed transcriptionally when DC3000 was treated with an extract from strain BR3. Importantly, the extract also influenced bacterial motility, the expression of type three secretion system effector AvrPto, and the plant hypersensitive response triggered by strain DC3000. The results suggested that the extract from strain BR3 might offer an alternative method to control bacterial diseases in plants by targeting the GacS/GacA system.
GacS/GacA双组分系统对许多植物致病细菌的毒力至关重要，因此是一个很有前景的抗毒力靶点。在本研究中，我们分离并筛选了能够抑制植物致病细菌丁香假单胞菌番茄致病变种（Pseudomonas syringae pv. tomato (Pst)）DC3000中某基因表达的根际细菌。通过16S rRNA基因序列分析，获得了一种候选抑制细菌BR3，并鉴定为芽孢杆菌属（Bacillus）菌株。当用BR3菌株的提取物处理DC3000时，除了该基因外，GacA依赖性小RNA基因RsmY和RsmZ的转录也受到抑制。重要的是，该提取物还影响细菌的运动性、三型分泌系统效应子AvrPto的表达以及DC3000菌株引发的植物过敏反应。结果表明，BR3菌株的提取物可能通过靶向GacS/GacA系统为控制植物细菌病害提供一种替代方法。
