quorum sensing in xanthomonas
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Transcript of quorum sensing in xanthomonas
Quorum Sensing in Xanthomonas
Narayan Prahlad V7th SemesterMolecular Biology
Contents Introduction Quorum sensing Xanthomonas Quorum sensing in Xanthomonas QS pathway Quorum sensing-Virulence Conclusion References
Introduction
Quorum SensingQuorum sensing (QS)-phenomenon-bacteria communicate among each other in a cell density dependent media to regulate their gene expression by- release of certain molecules.
Signaling molecules-two main chemical categories: N-acyl homoserine lactones (AHLs)- autoinducer-1 (AI-1)-characteristic of Gram-negative
bacteria; autoinducing peptides (AIPs)-Gram-positive bacteria.
Chemically different signaling molecules have also been identified-
A-factor from Streptomyces (γ-butyrolactone), 4-quinolones Pseudomonas Quinolone Signal -PQS fatty acids (Diffusible Signal Factors-DSF).
General mechanism of QS
(Steven T. Rutherford1 and Bonnie L. Bassler-2012)
Xanthomonas Kingdom -Bacteria
Phylum -Proteobacteria
Class -Gammaproteobacteria
Order -Xanthomonadales
Family -Xanthomonadaceae
Genus -Xanthomonas
Size of Genomic DNA - 4.17 Mbp- 5.12 Mbp
Electron Microscopic image of Xanthomonas
X. campestris pv campestris, X. citri.
Citrus cankerBacterial leaf spot
Xanthomonas oryzae. pv. oryzae -Bacterial Blight (BB)
X .oryzae pv oryzicola bacterial leaf streak (BLS).
Electron Microscopic Image of Xoo in Xylem vessel of Rice
QS in XanthomonasQS takes place by production of- Diffusible Signal Factor (DSF).
The perception of these signals can influence different aspects of bacterial behavior like biofilm formation, synthesis of virulence factors etc.
(cis-11-methyl-2-dodecenoic acid)
DSF- Diffusible Signal FactorSynthesised by gene- rpf.
rpfF- DSF Synthase.
Robert P. Ryan and J. Maxwell Dow-2011
DSF Synthase
Ya-Wen He & Lian-Hui Zhang-2008
QS Pathway-Cell Density
Ya-Wen He & Lian-Hui Zhang-2008
QS Pathway-
Daniela Buttner & Ulla Bonas-2009
Quorum Sensing-VirulenceDegree of infection- Virulence
1) Extracellular polysaccharide (EPS)
2) Biofilm
3) Lipopolysacharide
EPS Biofilm
(Rai et.al 2015)
Gram –ve Cell wall
Xcc Xoo
Effect of Fungal Endophytes-Xanthomonas oryzae
Sonika Jha-2014 unpublished
List of Endophytes
Fungus HostA. Alternaria Catheranhus roseusB. Arthirinium Elaeocarpus serratusC. Aspergillus Altingea excelsaD. Bartalinia BT-cottonE. Botrytis Erythroxylon monogynumF. Chaetomium BT-cottonG. Colletrotrichum BT-cottonH. Corynespora Entada rheediI. Curvularia Pedilanthus tithymaloidesJ. Cylindrocladium Piper mullesuaK. Dendryphion Coldenia procumbensL. Drechslera Coldenia procumbensM. Fusarium Sargassum wightiiN. Gilmaniella Datura metalO. Humicola Datura metalP. Lasiodiplodia theobromae Coelogyne sp.(Orchid)Q. Nigrospora Leucas asperaR. Penicillium BT-cottonS. Pestalotiopsis Syzgium cuminiT. Phomopsis NBT-cottonU. Phylosticta Turpinia nepalensisV. Pithomyces Eurya nitidaW. Trichocladium Datura metalX. Trichoderma harzianum Sargassum wightiiY. Xylaria Zizyphyus jujuba
TechniquePrimary culture-Rifampicin, Cyclohexamide (CHM) and Cephalaxin (CPL)
Secondary culture- 0.2% Primary culture
Control- only culture
Methanol control (MC)- culture + methanol
20μl fungal endophytes was added.
Incubated for 44 hours
O.D-600 nm
Effect of Fungal Endophytes- Xanthomonas campestris
Sonika Jha-2014 unpublished
Effect of Fungal Endophytes- Alternaria
Xom/C Xom/MC Xom/20μl Xom/25μl Xom/30μl Xcc/C Xcc/MC Xcc/20μl Xcc/25μl Xcc/30μl0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
Endophyte from Alternaria (Crude Extract)
Strains
O.D
at 6
00 n
m a
fter
24 H
ours
TechniquePrimary culture of Xoo and Xcc-Rifampicin, Cyclohexamide (CHM) and Cephalaxin (CPL)
Secondary culture- 0.2% Primary culture
Control- only culture
Methanol control (MC)- culture + methanol
20,25 and 30μl endophyte from Alternaria was added to both.
Incubated for 24 hours
O.D-600 nm
Conclusion
QS plays an important role in bacteria during pathogenesis.
some marine organisms- Squids.
The light organ is colonized by a large number of Vibrio fischeri - autoinducer accumulates to a threshold concentration, triggering light production.
These examples of cell-cell communication demonstrate what might be called multicellular behavior in that many individual cells communicate and coordinate their activities to act as a unit.
Xanthan- used as a food additive-as a food thickening agent (in salad dressings, for example)
stabilizer (in cosmetic products, for example, to prevent ingredients from separating).
Structure of Xanthan
ReferencesDaniela Buttner & Ulla Bonas (2009); Regulation and secretion of Xanthomonas virulence factors. FEMS Microbiol Rev 34 (2010); 107- 121.
DAVID O. NIÑO-LIU PAMELA C. RONALD AND ADAM J. BOGDANOVE (2006); Xanthomonas oryzae pathovars: model pathogens of a model crop. 2006 BLACKWELL PUBLISHING LTD.303-310.
Robert P. Ryan and J. Maxwell Dow (2011); Communication with a growing family: diffusible signal factor (DSF) signaling in bacteria. Trends in Microbiology March 2011, Vol. 19, No. 3; Cell Press.145-150.
Ya Wen He et.al; Quorum sensing and virulence regulation in Xanthomonas campestris; 2008; Institute of Molecular and Cell Biology, Singapore, Singapore; FEMS Microbiol Rev; 842-854
Steven T. Rutherford1 and Bonnie L. Bassler (2012); Bacterial Quorum Sensing: Its Role in Virulence
and Possibilities for Its Control Cold Spring Harb Perspect Med 2012;2: a012427. Cold Spring Harbor Laboratory Press. 2012; 1-3, 9-11
Robert P. Ryan and J. Maxwell Dow (2011); Communication with a growing family: diffusible signal factor (DSF) signaling in bacteria. Trends in Microbiology March 2011, Vol. 19, No. 3; Cell Press.145-150.
Christopher M.Waters and Bonnie L. Bassler (2005). Quorum Sensing: Cell-to-Cell Communication in Bacteria; Annu. Rev. Cell Dev. Biol. 2005.
Acknowledgements I would like to thank my guide R. Chandrakanth for his guidance.
I would also like to thank our course coordinator Dr. N.S Devaki for providing me this opportunity to present this seminar.
I would whole heartedly thank the members in the lab of Plant-Microbe Interaction, CDFD, Hyderabad.
Thank u all for your patience.
Thank You
Type II and III Secretion Systems6 types of Secretion systems (SS). Type I (T1S)- VI (T6S).
Vary in composition and function.
Not conserved.
T2S and T3S are very important during host-pathogen interaction.
Daniela Buttner & Ulla Bonas-2009T2S and T3S Systems
ControlCultural Methods-
At the nursery stage-
seed disinfection, proper nursery drainage, and removal of diseased plants, weeds and debris.
Prior to transplanting, fields-disinfected by burning rice straw left from the previous season.
Weeds-removed from canals and ridges in order to reduce natural habitats for the pathogen and its dispersal through irrigation water.
Paddy field stage, judicious fertilization and proper plant spacing are the most recommended cultural methods of control.
Chemical Methods-
Bordeaux mixture (hydrated lime and copper sulfate) , several antibiotics, mercuric and copper compounds.
Inefficent- damage rice grains when sprayed.
In temperate regions, probenazole-added to the paddy water before and after transplanting the seedlings-to inhibit bacterial multiplication and prevent or retard the disease.
Other chemicals such as tecloftalam, phenazine oxide and nickel dimethyldithiocarbamate are sprayed directly on plants
However, chemical control of BB in the tropical monsoon climate of Asia is impractical, and no truly effective bactericide is commercially available for disease control.
Biological control-
Pseudomonas fluorescens and P. putida strain V14i (also used in biocontrol of the rice sheath blight pathogen Rhizoctonia solani) significantly suppressed BB severity when sprayed on leaves.
Breeding and deployment of resistant cultivars carrying major resistance (R ) genes-most effective approach to controlling BB.