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| − | {{Aix-Marseille}} | + | {{Aix-Marseille|title=KILL XYL|toc=__TOC__}} |
| − | <h1>KILL XYL</h1>
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| − | ==Abstract==
| + | [[File:T--Aix-Marseille--KX.png|500px|right|thumb|KILL XYL project.]] |
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| − | '''KILL XYL''' is a cure against the disease caused by ''Xylella fastidiosa'', a plant pathogene. Currently, no extensive cure exists against this disease that causes the loss of thousands of hectares of European crops. | + | Our project '''KILL XYL''' is to find a cure for the disease caused by the plant pathogen [[Team:Aix-Marseille/Xylella_fastidiosa|''Xylella fastidiosa'']]. This disease currently causes the loss of thousands of acres of European crops and currently there is no cure for it. |
| − | '''KILL XYL''' has the goal to detect the symptom of the disease, then use specific phage-like particles in order to inject toxins into ''X. fastidiosa''. Finally, with the help of fatty acid it quenches the quorum sensing activity of the bacterium and with an enzyme it degrades the biofilm, which is the principal cause of plants death.
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| − | To be specific to ''X. fastidiosa'', '''KILL XYL''' uses a specific phage-like particle able to recognize the pili and some extracellular proteins by which the bacterium can be identified in a background of millions.
| + | At Aix-Marseille University, we thought about developing a solution that focuses on multiple aspects. First, we wanted to improve [[Team:Aix-Marseille/Hardware|detection]] of the disease. To do this we used an NDVI camera that would help us to see if the plant is stressed or not. If the plant is infected by [[Team:Aix-Marseille/Xylella_fastidiosa|''Xylella fastidiosa'']], it suffers from a hydric stress that stops the photosynthesis. |
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| − | ==Motivation==
| + | Secondly, we wanted to get rid of the bacteria. |
| | + | Phages are natural predators of bacteria. |
| | + | They can also be used to transfer DNA into bacteria. |
| | + | Phages have the additional advantages of being strain specific and in some cases customizable. |
| | + | As we wanted an eco-friendly treatment |
| | + | to facilitate obtaining [[Team:Aix-Marseille/Legislation|marketing authorizations]], |
| | + | we decided to create [[Team:Aix-Marseille/Bacteriophages|phage-like particles]] (PLPs), that aren't able to spread. |
| | + | So we set out the construction of a phage specific to [[Team:Aix-Marseille/Xylella_fastidiosa|''X. fastidiosa'']], |
| | + | capable of injecting genes coding for toxic proteins into the bacteria. |
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| − | ''Xylella fastidiosa'' is a bacterium that infects the xylem tissues of a wide range of plants. This bacterium has been widespread in the Americas for many years and occurs also in Asia. The bacterium is associated with several diseases of crops of economic significance, and has a wide range of host plants comprising 312 species.
| + | The main cause of the plant mortality in the case of an infection by [[Team:Aix-Marseille/Xylella_fastidiosa|''X. fastidiosa'']] is hydric stress induced by the accumulation of biofilm in xylem vessels. |
| − | | + | To disrupt the biofilm we thought about two different approaches. |
| − | ''X. fastidiosa'' is transmitted from plant to plant by xylem sucking insects. The bacterium can persist in symptomless uncultivated plants, from which insects may acquire the bacterium and pass it to crops. Symptoms of disease are only observed when xylem vessels are highly colonized by the bacterium. The xylem transports water and soluble mineral, nutrients from the roots throughout the plant, and used to replace water lost during transpiration and photosynthesis. Xylem vessels are interconnected by bordered pits, which allow the passage of xylem sap, but block the passage of larger objects (such as bacterium) by a membrane.
| + | The first is to keep the bacteria from producing extra-cellular polysaccharides. |
| − | | + | We achieve this by [[Team:Aix-Marseille/QS|quenching bacterial quorum sensing]] using a short chain fatty acid called: 2-cis-decenoic acid. |
| − | The control of the movement of potential hosts and insect vectors and the eradication of infected material is considered the most effective method of limiting the spread of the disease in the European Union. But there is no method yet to cure the trees.
| + | The second approach is to destroy the biofilm's exo-polysaccharides using an [[Team:Aix-Marseille/DEPS|enzyme]] obtained from a bacteriophage to hydrolyse the polysaccharides. |
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| − | [[File:T--Aix-Marseille--Xylellaworld.png|900px|center|thumb|Distribution map of ''Xylella fastidiosa'' worldwide.]] | + | |
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| − | ==KILL XYL concept==
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| − | At Aix-Marseille University we thought about a solution that enclose many aspect of the cure.
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| − | [[File:T--Aix-Marseille--KXpro.png|400px|center|thumb|KILL XYL project.]]
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| − | First, we wanted to improve the detection of the disease, to do so we wanted to use a NDVI camera that will help us to see if the plant do photosynthesis or not. If the plant is heavily affected by ''Xylella fastidiosa'', it support a hydric stress that stop the photosynthesis.
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| − | Secondly, we want to get rid of the bacterium. Phages are natural predators of bacteria. They can also be used to transfect DNA into a bacterial cell. Phages has also the advantage of being specific to a strain and to be modulable. As we wanted to be eco-friendly, we create phage-likes particles, that aren't able to spread. Thus we have nanobots specific to ''Xylella fastidiosa'', capable to inject toxic genes into the bacterium.
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| − | The main cause of the plants death, is the hydric stress induced by the accumulation of biofilm into the xylem vessels. To disrupt the biofilm we thought about different solutions. The first one is to stop the bacterium producing any extra poly-saccharide. This could be achieved by quenching the quorum sensing of the bacterium with the help of a little fatty acid called : 2-cis-decenoic acid. Secondly, we wanted to destroy the exo-polysaccharids. An enzyme coming from a bacteriophage could fulfill the use by the hydrolysis of polysaccharides.
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| − | Hence, '''KILL XYLL''' simply detects, disrupt and kill ''Xylella fastidiosa''.
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| − | ===Module 1: Detection of the disease===
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| − | ===Module 2 : Engineering bacteriophages===
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| − | [[File:T--Aix-Marseille--PhageEng.png|400px|center|thumb|Phage-like particles process.]]
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| − | Bacteriophages play a special role in nanoscale cargo-delivery developments, because they can be regarded as naturally occurring nanomaterials. Viral nanoparticles (VNPs), in particular bacteriophages, are attractive options for cargo-delivery as they are biocompatible, biodegradable, and non-infectious to mammals.
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| − | Phage systems, like M13, have been employed in biotechnological applications, most prominently in the identification and maturation of medically-relevant binding molecules through phage display. The application of phages in materials and nanotechnology is mainly due to their nanoscale size and simple life cycles. We choose to use those application in our advantage in order to target ''Xylella fastidiosa'' and other pathogenic bacteria.
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| − | [[Team:Aix-Marseille/Bacteriophages|Read more…]] | + | |
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| − | ===Module 3 : Quorum sensing approach===
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| − | ''Xylella fastidiosa'' uses quorum sensing, as an inter-bacterial communication system, to regulate its biofilm production. The quorum sensing is based on the emission of specific fatty acid, there are fatty acids antagonistic to its quorum sensing, this disturbance is called quorum quenching. 2-cis-decenoic acid is one of these fatty acids whom has quorum quenching effect to ''Xylella fastidiosa''. This action of quenching will prevent the formation of biofilm, dependent of the quorum sensing and therefore will have both action preventive and curative to the symptoms caused by the biofilm on the plants. We want to produce this fatty acids from ''E. coli'' to inoculated the infected trees. Thus saving the plants from ''Xylella fastidiosa''.
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| − | [[Team:Aix-Marseille/QS|Read more…]]
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| − | ===Module 4 : Disrupting the biofilm===
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| − | [[Team:Aix-Marseille/DEPS|Read more…]] | + | |
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| − | ==InterLab==
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| − | We used plasmids containing different promoter from the 2017 distribution kit and transfect into ''E.coli''. Before measuring fluorescence expression, we used LUDOX and fluorescein to calibrate the TECAN. We prepared a dilution series of fluorescein in 4 replicates and measure the fluorescence in a 96 well plate in a plate reader. By measuring these in all standard modes, we generated a standard curve of fluorescence for fluorescein concentration. We used this to correct cell based readings to an equivalent fluorescein concentration and convert this into a concentration of GFP.
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| − | [[Team:Aix-Marseille/InterLab|Read more…]]
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| − | <html>
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| − | <div class="column full_size">
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| − | <h1>Description</h1>
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| − | <p>Tell us about your project, describe what moves you and why this is something important for your team.</p>
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| − | <h5>What should this page contain?</h5>
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| − | <ul>
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| − | <li> A clear and concise description of your project.</li>
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| − | <li>A detailed explanation of why your team chose to work on this particular project.</li>
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| − | <li>References and sources to document your research.</li>
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| − | <li>Use illustrations and other visual resources to explain your project.</li>
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| − | </ul>
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| | + | Hence, '''KILL XYL''' simply detects the disease, disrupts biofilm and kills [[Team:Aix-Marseille/Xylella_fastidiosa|''Xylella fastidiosa'']]. |
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| | + | <div class="row-icons"> |
| | + | * [[File:T--Aix-Marseille--drone.png|link=Team:Aix-Marseille/Hardware]]<span class="legend">Detection</span> |
| | + | * [[File:T--Aix-Marseille--icon-phage.png|link=Team:Aix-Marseille/Bacteriophages]]<span class="legend">Engineering PLPs</span> |
| | + | * [[File:T--Aix-Marseille--icon-QS.png|link=Team:Aix-Marseille/QS]]<span class="legend">Quorum sensing</span> |
| | + | * [[File:T--Aix-Marseille--icon-deps.png|link=Team:Aix-Marseille/DEPS]]<span class="legend">Disrupting biofilm</span> |
| | + | * [[File:T--Aix-Marseille--icon-model.png|link=Team:Aix-Marseille/Model]]<span class="legend">Modelling</span> |
| | </div> | | </div> |
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| − | <h5>Advice on writing your Project Description</h5>
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| − | We encourage you to put up a lot of information and content on your wiki, but we also encourage you to include summaries as much as possible. If you think of the sections in your project description as the sections in a publication, you should try to be consist, accurate and unambiguous in your achievements.
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| − | Judges like to read your wiki and know exactly what you have achieved. This is how you should think about these sections; from the point of view of the judge evaluating you at the end of the year.
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| − | </p>
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| − | <h5>References</h5>
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| − | <p>iGEM teams are encouraged to record references you use during the course of your research. They should be posted somewhere on your wiki so that judges and other visitors can see how you thought about your project and what works inspired you.</p>
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| − | <h5>Inspiration</h5>
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| − | <p>See how other teams have described and presented their projects: </p>
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| − | <ul>
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| − | <li><a href="https://2016.igem.org/Team:Imperial_College/Description">2016 Imperial College</a></li>
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| − | <li><a href="https://2016.igem.org/Team:Wageningen_UR/Description">2016 Wageningen UR</a></li>
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| − | <li><a href="https://2014.igem.org/Team:UC_Davis/Project_Overview"> 2014 UC Davis</a></li>
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| − | <li><a href="https://2014.igem.org/Team:SYSU-Software/Overview">2014 SYSU Software</a></li>
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| − | </ul>
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| − | </html>
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KILL XYL
Our project KILL XYL is to find a cure for the disease caused by the plant pathogen Xylella fastidiosa. This disease currently causes the loss of thousands of acres of European crops and currently there is no cure for it.
At Aix-Marseille University, we thought about developing a solution that focuses on multiple aspects. First, we wanted to improve detection of the disease. To do this we used an NDVI camera that would help us to see if the plant is stressed or not. If the plant is infected by Xylella fastidiosa, it suffers from a hydric stress that stops the photosynthesis.
Secondly, we wanted to get rid of the bacteria.
Phages are natural predators of bacteria.
They can also be used to transfer DNA into bacteria.
Phages have the additional advantages of being strain specific and in some cases customizable.
As we wanted an eco-friendly treatment
to facilitate obtaining marketing authorizations,
we decided to create phage-like particles (PLPs), that aren't able to spread.
So we set out the construction of a phage specific to X. fastidiosa,
capable of injecting genes coding for toxic proteins into the bacteria.
The main cause of the plant mortality in the case of an infection by X. fastidiosa is hydric stress induced by the accumulation of biofilm in xylem vessels.
To disrupt the biofilm we thought about two different approaches.
The first is to keep the bacteria from producing extra-cellular polysaccharides.
We achieve this by quenching bacterial quorum sensing using a short chain fatty acid called: 2-cis-decenoic acid.
The second approach is to destroy the biofilm's exo-polysaccharides using an enzyme obtained from a bacteriophage to hydrolyse the polysaccharides.
Hence, KILL XYL simply detects the disease, disrupts biofilm and kills Xylella fastidiosa.
-
Detection
-
Engineering PLPs
-
Quorum sensing
-
Disrupting biofilm
-
Modelling
