AUTHOR=Ye Tian , Zhou Tian , Fan Xinghui , Bhatt Pankaj , Zhang Lianhui , Chen Shaohua 

TITLE=Acinetobacter lactucae Strain QL-1, a Novel Quorum Quenching Candidate Against Bacterial Pathogen Xanthomonas campestris pv. campestris

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02867

DOI=10.3389/fmicb.2019.02867

ISSN=1664-302X

ABSTRACT=<p>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 <italic>Xanthomonas campestris</italic> pv. <italic>campestris</italic> (<italic>Xcc</italic>) 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 <italic>Xcc</italic>. The results indicated that a novel DSF-degrading bacterium, <italic>Acinetobacter lactucae</italic> QL-1, effectively attenuated <italic>Xcc</italic> virulence through quorum quenching. Lab-based experiments indicated that plants inoculated with QL-1 and <italic>Xcc</italic> had less tissue decay than those inoculated with <italic>Xcc</italic> alone. Co-inoculation of strains <italic>Xcc</italic> 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 <italic>Xcc</italic>. 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.</p>