Agriculture Reference
In-Depth Information
III.
C
ONCLUSION
The discovery of the QS mechanism as a widespread system for the control of
synchronized gene expression in microorganisms in response to cell density has radically
changed the conception of microbial communities, which are now understood as organized
groups whose members are in constant communication and take global decisions, acting as
multicellular organisms. The existence of many bacterial phenotypes of interest for humans
that are regulated by intercellular communication provides a possibility to modify or
modulate externally the bacterial responses, by interfering transmission and/or reception of
their signal molecules. Advances in the knowledge and understanding of QS signaling
systems, and identification of quorum quenching mechanisms in nature, will notably help to
design new improved methods for the control of infectious diseases and biofilm formation.
The study of the extent of the influence of QS systems in plant-bacterial interactions, and
particularly on the establishment and performance of the rhizobia-legume symbiosis, is a task
still in progress, as intercellular signaling is likely to play important roles for strain survival,
colonization of plant roots, infection, and nodule development. Better understanding of these
mechanisms may also allow the manipulation of QS systems for the improvement of the
efficiency of inoculant strains.
IV.
R
EFERENCES
Aendekerk, S., Diggle
S.P., Song
,
Z., Høiby, N., Cornelis, P., Williams,
P., and Cámara, M.
(2005). The MexGHI-OpmD multidrug efflux pump controls growth, antibiotic
susceptibility and virulence in
Pseudomonas aeruginosa
via 4-quinolone-dependent cell-
to-cell communication.
Microbiology 151
,1113-1125.
Balaban, N., and Novick, R.P. (1995). Autocrine regulation of toxin synthesis by
Staphylococcus aureus. Proceedings of the National Academy of Sciences of the USA
92
,1619-1623.
Barnard, A. M. L., Bowden, S. D., Burr, T., Coulthurst, S. J., Monson, R. E., and Salmond, G.
P. C. (2007). Quorum sensing, virulence and secondary metabolite production in plant
soft-rotting bacteria.
Philosophical Transactions of the Royal Society B
362
, 1165-1183.
Bassler, B. L., Wright, M., Showalter, R. E., and Silverman, M. R. (1993). Intercellular
signaling in
Vibrio harveyi
- sequence and function of genes regulating expression of
luminescence.
Molecular Microbiology 9
, 773-786.
Bauer, W.D., and Robinson, J.B. (2002) Disruption of bacterial quorum sensing by other
organisms.
Current Opinion in Biotechnology 13,
234-237.
Bauer, W.D., and Mathesius, U. (2004). Plant responses to bacterial quorum sensing signals.
Current Opinion in Plant Biology 7
, 429-233.
Bjarnsholt, T., and Givskov, M. (2007) Quorum-sensing blockade as a strategy for enhancing
host defences against bacterial pathogens.
Philosophical Transactions of the Royal
Society B
362, 1213-1222.
Camilli, A., and Bassler, B.L. (2006). Bacterial small-moleculre signaling pathways.
Science
311
, 1113-1116.
