Ye Tian, Zhou Tian, Fan Xinghui, Bhatt Pankaj, Zhang Lianhui, Chen Shaohua
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.
Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China.
Front Microbiol. 2019 Dec 17;10:2867. doi: 10.3389/fmicb.2019.02867. eCollection 2019.
Quorum sensing (QS) is a cell-cell communication mechanism among bacterial populations that is regulated through gene expression in response to cell density. The pathogenicity of pv. () is modulated by the diffusible signal factor (DSF)-mediated QS system. DSF is widely conserved in a variety of gram-negative bacterial pathogens. In this study, DSF-degrading bacteria and their enzymes were thoroughly explored as a biocontrol agent against . The results indicated that a novel DSF-degrading bacterium, QL-1, effectively attenuated virulence through quorum quenching. Lab-based experiments indicated that plants inoculated with QL-1 and had less tissue decay than those inoculated with alone. Co-inoculation of strains and QL-1 significantly reduced the incidence and severity of disease in plants. Similarly, the application of crude enzymes of strain QL-1 substantially reduced the disease severity caused by . The results showed that strain QL-1 and its enzymes possess promising potential, which could be further investigated to better protect plants from DSF-dependent pathogens.
群体感应（QS）是细菌群体间的一种细胞间通讯机制，通过基因表达响应细胞密度进行调控。丁香假单胞菌致病变种（Pseudomonas syringae pv.）的致病性受可扩散信号因子（DSF）介导的群体感应系统调节。DSF在多种革兰氏阴性细菌病原体中广泛存在。在本研究中，对降解DSF的细菌及其酶作为针对丁香假单胞菌致病变种的生物防治剂进行了深入探索。结果表明，一种新型的降解DSF细菌QL-1通过群体淬灭有效减弱了丁香假单胞菌致病变种的毒力。基于实验室的实验表明，接种QL-1和丁香假单胞菌致病变种的植物比单独接种丁香假单胞菌致病变种的植物组织腐烂更少。菌株QL-1和丁香假单胞菌致病变种共同接种显著降低了植物疾病的发病率和严重程度。同样，菌株QL-1的粗酶应用也大幅降低了丁香假单胞菌致病变种引起的疾病严重程度。结果表明，菌株QL-1及其酶具有广阔的应用潜力，可进一步研究以更好地保护植物免受依赖DSF的病原体侵害。
