Difference between revisions of "Team:Aix-Marseille/Project"

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{{Aix-Marseille|title=KILL XYL|toc=__TOC__}}
 
{{Aix-Marseille|title=KILL XYL|toc=__TOC__}}
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==Abstract==
 
  
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Our project, '''KILL XYL''' will be a cure against the disease caused by the plant pathogen ''Xylella fastidiosa''. This disease currently causes the loss of thousands of hectares of European crops and no extensive cure exists against it.
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[[File:T--Aix-Marseille--KX.png|500px|right|thumb|KILL XYL project.]]
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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.
 
   
 
   
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'''KILL XYL''' has a two step approach. Since the symptoms of disease are only observed when xylem vessels are highly colonized by the bacterium and photosynthesis is blocked, we first detect the symptoms of the disease using a drone equipped with a camera.
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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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We will then treat the disease with a combination of three strategies. To directly attack the bacterium, we developed specific phage-like particles that inject toxins. To disrupt the biofilm, which is the principal cause of plants death, a particular fatty acid that quenches the quorum sensing activity of the bacterium and an enzyme that degrades the biofilm will be used.
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==Motivation==
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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.
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''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.
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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.
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[[File:T--Aix-Marseille--Xylellaworldwide.png|1000px|Distribution map of ''Xylella fastidiosa'' worldwide.]]
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[[Team:Aix-Marseille/Xylella_fastidiosa]]
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==KILL XYL concept==
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[[File:T--Aix-Marseille--KX.png|1000px|KILL XYL project.]]
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[[Team:Aix-Marseille/KXconcept|Read more…]]
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==Modelling==
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Secondly, we wanted to get rid of the bacteria.
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Phages are natural predators of bacteria.
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They can also be used to transfer DNA into bacteria.
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Phages have the additional advantages of being strain specific and in some cases customizable.
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As we wanted an eco-friendly treatment
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to facilitate obtaining [[Team:Aix-Marseille/Legislation|marketing authorizations]],
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we decided to create [[Team:Aix-Marseille/Bacteriophages|phage-like particles]] (PLPs), that aren't able to spread.
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So we set out the construction of a phage specific to [[Team:Aix-Marseille/Xylella_fastidiosa|''X. fastidiosa'']],
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capable of injecting genes coding for toxic proteins into the bacteria.
  
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==InterLab==
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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.
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To disrupt the biofilm we thought about two different approaches.
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The first is to keep the bacteria from producing extra-cellular polysaccharides.
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We achieve this by [[Team:Aix-Marseille/QS|quenching bacterial quorum sensing]] using a short chain fatty acid called: 2-cis-decenoic acid.
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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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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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Hence, '''KILL XYL''' simply detects the disease, disrupts biofilm and kills [[Team:Aix-Marseille/Xylella_fastidiosa|''Xylella fastidiosa'']].
  
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[[Team:Aix-Marseille/InterLab|Read more…]]
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<div class="row-icons">
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* [[File:T--Aix-Marseille--drone.png|link=Team:Aix-Marseille/Hardware]]<span class="legend">Detection</span>
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* [[File:T--Aix-Marseille--icon-phage.png|link=Team:Aix-Marseille/Bacteriophages]]<span class="legend">Engineering PLPs</span>
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* [[File:T--Aix-Marseille--icon-QS.png|link=Team:Aix-Marseille/QS]]<span class="legend">Quorum sensing</span>
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* [[File:T--Aix-Marseille--icon-deps.png|link=Team:Aix-Marseille/DEPS]]<span class="legend">Disrupting biofilm</span>
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* [[File:T--Aix-Marseille--icon-model.png|link=Team:Aix-Marseille/Model]]<span class="legend">Modelling</span>
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</div>

Latest revision as of 23:37, 1 November 2017

KILL XYL

KILL XYL project.

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.

  • T--Aix-Marseille--drone.pngDetection
  • T--Aix-Marseille--icon-phage.pngEngineering PLPs
  • T--Aix-Marseille--icon-QS.pngQuorum sensing
  • T--Aix-Marseille--icon-deps.pngDisrupting biofilm
  • T--Aix-Marseille--icon-model.pngModelling