ChpA Controls Twitching Motility and Broadly Affects Gene Expression in the Biological Control Agent Lysobacter enzymogenes

2017 ◽  
Vol 74 (5) ◽  
pp. 566-574 ◽  
Author(s):  
Mimi Zhou ◽  
Danyu Shen ◽  
Gaoge Xu ◽  
Fengquan Liu ◽  
Guoliang Qian
Keyword(s):  
Gene Expression ◽  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Twitching Motility ◽  
Lysobacter Enzymogenes

scholarly journals The Effect of Aspergillus Thermomutatus Chrysovirus 1 on the Biology of Three Aspergillus Species

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 539 ◽  
Author(s):  
Mahjoub A. Ejmal ◽  
David J. Holland ◽  
Robin M. MacDiarmid ◽  
Michael N. Pearson
Keyword(s):  
Gene Expression ◽  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Aspergillus Species ◽  
Expression Data ◽  
Altered Gene Expression ◽  
Large Numbers ◽  
Altered Gene ◽  
Infected Line

This study determined the effects of Aspergillus thermomutatus chrysovirus 1 (AthCV1), isolated from Aspergillus thermomutatus, on A. fumigatus, A. nidulans and A. niger. Protoplasts of virus-free isolates of A. fumigatus, A. nidulans and A. niger were transfected with purified AthCV1 particles and the phenotype, growth and sporulation of the isogenic AthCV1-free and AthCV1-infected lines assessed at 20 °C and 37 °C and gene expression data collected at 37 °C. AthCV1-free and AthCV1-infected A. fumigatus produced only conidia at both temperatures but more than ten-fold reduced compared to the AthCV1-infected line. Conidiation was also significantly reduced in infected lines of A. nidulans and A. niger at 37 °C. AthCV1-infected lines of A. thermomutatus and A. nidulans produced large numbers of ascospores at both temperatures, whereas the AthCV1-free line of the former did not produce ascospores. AthCV1-infected lines of all species developed sectoring phenotypes with sclerotia produced in aconidial sectors of A. niger at 37 °C. AthCV1 was detected in 18% of sclerotia produced by AthCV1-infected A. niger and 31% of ascospores from AthCV1-infected A. nidulans. Transcriptome analysis of the naturally AthCV1-infected A. thermomutatus and the three AthCV1-transfected Aspergillus species showed altered gene expression as a result of AthCV1-infection. The results demonstrate that AthCV1 can infect a range of Aspergillus species resulting in reduced sporulation, a potentially useful attribute for a biological control agent.

scholarly journals PilG is Involved in the Regulation of Twitching Motility and Antifungal Antibiotic Biosynthesis in the Biological Control Agent Lysobacter enzymogenes

2015 ◽  
Vol 105 (10) ◽  
pp. 1318-1324 ◽  
Author(s):  
Xue Zhou ◽  
Guoliang Qian ◽  
Yuan Chen ◽  
Liangcheng Du ◽  
Fengquan Liu ◽  
...  
Keyword(s):  
Biological Control ◽  
Secondary Metabolite ◽  
Fungal Pathogens ◽  
Biological Control Agent ◽  
Response Regulator ◽  
Regulatory Protein ◽  
Antibiotic Biosynthesis ◽  
Twitching Motility ◽  
Control Activity ◽  
Lysobacter Enzymogenes

Lysobacter enzymogenes strain C3 is a gliding bacterium which produces the antifungal secondary metabolite heat-stable antifungal factor (HSAF) and type IV pilus (T4P) as important mechanisms in biological control activity against fungal pathogens. To date, the regulators that control HSAF biosynthesis and T4P-dependent twitching motility in L. enzymogenes are poorly explored. In the present study, we addressed the role of pilG in the regulation of these two traits in L. enzymogenes. PilG of L. enzymogenes was found to be a response regulator, commonly known as a component of a two-component transduction system. Mutation of pilG in strain C3 abolished its ability to display spreading colony phenotype and cell movement at the colony margin, which is indicative of twitching motility; hence, PilG positively regulates twitching motility in L. enzymogenes. Mutation of pilG also enhanced HSAF production and the transcription of its key biosynthetic gene hsaf pks/nrps, suggesting that PilG plays a negative regulatory role in HSAF biosynthesis. This finding represents the first demonstration of the regulator PilG having a role in secondary metabolite biosynthesis in bacteria. Collectively, our results suggest that key ecological functions (HSAF production and twitching motility) in L. enzymogenes strain C3 are regulated in opposite directions by the same regulatory protein, PilG.

scholarly journals Roles of a Solo LuxR in the Biological Control Agent Lysobacter enzymogenes Strain OH11

2014 ◽  
Vol 104 (3) ◽  
pp. 224-231 ◽  
Author(s):  
Guoliang Qian ◽  
Feifei Xu ◽  
Vittorio Venturi ◽  
Liangcheng Du ◽  
Fengquan Liu
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Cell Aggregation ◽  
Antimicrobial Activities ◽  
Control Agent ◽  
Lytic Enzymes ◽  
Lysobacter Enzymogenes ◽  
Novel Structure ◽  
C Terminus ◽  
Visible Effect

Lysobacter enzymogenes is a ubiquitous plant-associated and environmentally friendly bacterium emerging as a novel biological control agent of plant disease. This bacterium produces diverse antifungal factors, such as lytic enzymes and a secondary metabolite (heat-stable antifungal factor [HSAF]) having antifungal activity with a novel structure and mode of action. The regulatory mechanisms for biosynthesis of antifungal factors is largely unknown in L. enzymogenes. The solo LuxR proteins have been shown to be widespread, playing important roles in plant-associated bacteria. Here, we cloned and studied a solo LuxR protein, LesR, from L. enzymogenes strain OH11. Overexpression but not deletion of lesR significantly impaired HSAF biosynthesis levels and antimicrobial activities but did not show visible effect on production of major lytic enzymes. Overexpression of lesR also led to remarkably accelerated cell aggregation and induced production of a melanin-like pigment in L. enzymogenes; these two phenotypes are mediated by the diffusible factor cell-to-cell signaling system of L. enzymogenes. The C-terminus helix-turn-helix domain was shown to be critical for several lesR-controlled functions. Overall, our study provides the first example of the roles and mechanisms of a solo LuxR protein in a plant-associated L. enzymogenes.

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