The impact of plant volatiles on bacterial quorum sensing

Abstract

Antimicrobial and antiquorum sensing (QS) properties of 29 common essential oil compounds were evaluated. Interruption of QS may lead to the development of therapeutic, antivirulence agents to control disease-causing pathogens which are preferable over antimicrobial agents as the latter drives selection pressure on microbial communities to acquire resistance. Twenty-two compounds inhibited QS, while seven promoted the QS to a variable extent in Chromobacterium violaceum and Pseudomonas aeruginosa. Preliminary results suggest that QS-inhibitory compounds of natural origin may inspire the formulation of new generation of antimicrobial agents to control infectious pathogens.

Shoot the Message, Not the Messenger—Combating Pathogenic Virulence in Plants by Inhibiting Quorum Sensing Mediated Signaling Molecules

“…However, plants have the capacity to produce secondary metabolites in smaller amounts. The considerable amount of natural anti-microbial molecule production in plants is achieved through various methods like the suspension hairy root culture and concentrations of such produced compounds were found to be sufficient for virulence suppression (Ahmad et al, 2014). Similarly, a monoterpenoid phenol carvacol demonstrated QS inhibition in bacteria, which limited biofilm formation and/or chitinase production (Borges et al, 2013; Kerekes et al, 2013; Burt et al, 2014).…”

Advances in Chromobacterium violaceum and properties of violacein-Its main secondary metabolite: A review

“…Volatile secondary metabolites purified from plants, such as (+) enantiomers of limonene, carvone and borneol increased violacein production in C. violaceum ATCC 12472, while (−) enantiomers acted as QS antagonists. Particularly, α-terpineol and Z-3-nonen-1-ol were found to inhibit violacein synthesis by more than 90% (Ahmad et al, 2014). Alternatively, screening for QS quenchers in marine organisms was performed with relative success.…”

“…The SHL molecules containing phenyl groups substituted in the ortho position with fluoride or chloride showed the best inhibitory effect on violacein production at about 1.5 μmol·dm −3 . Another strategy to find QS quenchers was used in the study of volatile plant molecules able to trigger QS signals (Ahmad et al, 2014). Volatile secondary metabolites purified from plants, such as (+) enantiomers of limonene, carvone and borneol increased violacein production in C. violaceum ATCC 12472, while (−) enantiomers acted as QS antagonists.…”

The ecological role of volatile mediated interactions belowground

“…However, VOCs released by roots including terpenes can also serve as carbon source (Kleinheinz et al 1999;Owen et al 2007;Del Giudice et al 2008) or function as infochemicals in plant-microbe interactions. For example, Ahmad et al (2015) revealed that plant VOCs such as carvone, limonene, and borneol stimulated bacterial QS while α-terpineol and cis-3-nonen-1-ol inhibited bacterial QS.…”

“…VOCs are small compounds of low molecular weight, lipophilic character, with high vapor pressure and low boiling points (Effmert et al 2012;Bitas et al 2013;Lemfack et al 2014;Schmidt et al 2015). shown to promote bacterial quorum sensing (Ahmad et al 2015). Furthermore, maize plants release the sesquiterpene (E)-β-caryophyllene in the rhizosphere when attacked by root feeding beetle larvae resulting in enhanced attraction of nematodes (Van Tol et al 2001;Rasmann et al 2005;Ali et al 2010).…”