Quantifying Bacterial Surface Swarming Motility on Inducer Gradient Plates

PilZ Domain Protein FlgZ Mediates Cyclic Di-GMP-Dependent Swarming Motility Control in Pseudomonas aeruginosa

Journal of Bacteriology ◽

10.1128/jb.00196-16 ◽

2016 ◽

Vol 198 (13) ◽

pp. 1837-1846 ◽

Cited By ~ 55

Author(s):

Amy E. Baker ◽

Andreas Diepold ◽

Sherry L. Kuchma ◽

Jessie E. Scott ◽

Dae Gon Ha ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Fluorescent Protein ◽

Bacterial Species ◽

Dependent Manner ◽

Swarming Motility ◽

Content Type ◽

Bacterial Surface ◽

Important Regulator ◽

Green Fluorescent

ABSTRACTThe second messenger cyclic diguanylate (c-di-GMP) is an important regulator of motility in many bacterial species. InPseudomonas aeruginosa, elevated levels of c-di-GMP promote biofilm formation and repress flagellum-driven swarming motility. The rotation ofP. aeruginosa's polar flagellum is controlled by two distinct stator complexes, MotAB, which cannot support swarming motility, and MotCD, which promotes swarming motility. Here we show that when c-di-GMP levels are elevated, swarming motility is repressed by the PilZ domain-containing protein FlgZ and by Pel polysaccharide production. We demonstrate that FlgZ interacts specifically with the motility-promoting stator protein MotC in a c-di-GMP-dependent manner and that a functional green fluorescent protein (GFP)-FlgZ fusion protein shows significantly reduced polar localization in a strain lacking the MotCD stator. Our results establish FlgZ as a c-di-GMP receptor affecting swarming motility byP. aeruginosaand support a model wherein c-di-GMP-bound FlgZ impedes motility via its interaction with the MotCD stator.IMPORTANCEThe regulation of surface-associated motility plays an important role in bacterial surface colonization and biofilm formation. c-di-GMP signaling is a widespread means of controlling bacterial motility, and yet the mechanism whereby this signal controls surface-associated motility inP. aeruginosaremains poorly understood. Here we identify a PilZ domain-containing c-di-GMP effector protein that contributes to c-di-GMP-mediated repression of swarming motility byP. aeruginosa. We provide evidence that this effector, FlgZ, impacts swarming motility via its interactions with flagellar stator protein MotC. Thus, we propose a new mechanism for c-di-GMP-mediated regulation of motility for a bacterium with two flagellar stator sets, increasing our understanding of surface-associated behaviors, a key prerequisite to identifying ways to control the formation of biofilm communities.

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Swarming motility in plant-associated bacteria

Hellenic Plant Protection Journal ◽

10.1515/hppj-2016-0002 ◽

2016 ◽

Vol 9 (1) ◽

pp. 16-27 ◽

Cited By ~ 5

Author(s):

A. Venieraki ◽

P.Ch. Tsalgatidou ◽

D.G. Georgakopoulos ◽

M. Dimou ◽

P. Katinakis

Keyword(s):

Survival Advantage ◽

Ecological Niches ◽

Huge Number ◽

Swarming Motility ◽

Associated Bacteria ◽

Surface Movement ◽

Bacterial Surface ◽

Surface Motility ◽

Plant Surfaces

Summary Plant-associated environments harbor a huge number of diverse bacteria that compete and/or cooperate for the occupation of the most nutrient-rich ecological niches. Motility, a common trait among bacteria, has long been assumed to provide a survival advantage to skilful bacteria in invading these environments. Bacterial surface motility, such as swarming, a flagella-driven type of surface movement, although mostly observed and studied on agar substrates, is emerging as a major trait involved in many functions of plant-associated bacteria in regard to their ability to colonize and spread on their host. In this review, we address some novel swarming motility strategies, which enable bacteria to colonize, disperse and compete in plant surfaces.

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