Difference between revisions of "Team:Bordeaux/Template:OverviewTheProblem"
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<h6 align="justify"> This year, iGEM Bordeaux’s project is focused on Downy Mildew </h6> | <h6 align="justify"> This year, iGEM Bordeaux’s project is focused on Downy Mildew </h6> | ||
| − | <p align="justify" style="text-indent: 3vw;"> This disease, caused by an oomycete called <b> <i> Plasmopara viticola </i> </b>, is unfortunately famous in the Aquitaine region because it affects tens of hectares of Bordeaux vineyards and <b> threatens wine production </b>. It was originally observed in the United States in 1834 and has been most abundantly found in the northern and midwestern areas of the United States. Shortly after, the pathogen was introduced in European countries where it played a devastating role in the yield and production of their grapes, and consequently their wine. In <b>1878</b>, the <b>first cases of downy mildew were observed in France </b> in the region of Lyon and also in Swizerland and Italy. Even if some North American species have become resistant to this parasite through evolution, European species such as <i> Vitis vinifera </i> (the grapevine used for wine) are extremely sensitive. <b>Depending on the year </b>, production of grapes in France has been estimated to be at a <b>loss of 50% or more </b> and the <b>Aquitaine region | + | <p align="justify" style="text-indent: 3vw;"> This disease, caused by an oomycete called <b> <i> Plasmopara viticola </i> </b>, is unfortunately famous in the Aquitaine region because it affects tens of hectares of Bordeaux vineyards and <b> threatens wine production </b>. It was originally observed in the United States in 1834 and has been most abundantly found in the northern and midwestern areas of the United States. Shortly after, the pathogen was introduced in European countries where it played a devastating role in the yield and production of their grapes, and consequently their wine. In <b>1878</b>, the <b>first cases of downy mildew were observed in France </b> in the region of Lyon and also in Swizerland and Italy. Even if some North American species have become resistant to this parasite through evolution, European species such as <i> Vitis vinifera </i> (the grapevine used for wine) are extremely sensitive. <b>Depending on the year </b>, production of grapes in France has been estimated to be at a <b>loss of 50% or more </b> and the <b>Aquitaine region is particularly affected due to the favorable climate </b>. Because of numbers and results like these, downy mildew has been considered the most devastating disease caused by a filamentous pathogen to affect European vineyards and this has lead vineyards to search for effective measures to protect their vines. Unfortunately, most of these mesures have a bad environmental impact and pollute the surrounding regions. </p> |
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<h6 align="justify"> In 2015, vineyards are still threatened by the disease </h6> | <h6 align="justify"> In 2015, vineyards are still threatened by the disease </h6> | ||
Revision as of 11:30, 14 July 2015
This disease, caused by an oomycete called Plasmopara viticola , is unfortunately famous in the Aquitaine region because it affects tens of hectares of Bordeaux vineyards and threatens wine production . It was originally observed in the United States in 1834 and has been most abundantly found in the northern and midwestern areas of the United States. Shortly after, the pathogen was introduced in European countries where it played a devastating role in the yield and production of their grapes, and consequently their wine. In 1878, the first cases of downy mildew were observed in France in the region of Lyon and also in Swizerland and Italy. Even if some North American species have become resistant to this parasite through evolution, European species such as Vitis vinifera (the grapevine used for wine) are extremely sensitive. Depending on the year , production of grapes in France has been estimated to be at a loss of 50% or more and the Aquitaine region is particularly affected due to the favorable climate . Because of numbers and results like these, downy mildew has been considered the most devastating disease caused by a filamentous pathogen to affect European vineyards and this has lead vineyards to search for effective measures to protect their vines. Unfortunately, most of these mesures have a bad environmental impact and pollute the surrounding regions. Our iGEM team has been following this year's effect of mildew closely reading the official vineyard mildew bulletins available on the vinopole website. It is clearly shown that there is a significant increase of mildew infection on parcels that haven't been treated with copper sulfate compared to those that have been treated. Furthermore, the infection of mildew on treated parcels appears to be much more easily controled on parcels treated with copper sulfate. Evidently, without any alternative treatment, wine production in the region would be affected and this shows just how important our project is! Different models (Caffi model, Potential systems model) take into account pluviometry, temperature, relative humidity and plant morphology to decide when are the best moments to apply the fungicides. However, even if these models have allowed vinyards to drastically reduce the quantities of fungicides used, they still cause environmental and sanitary problems in the surrounding regions. In the past few months (June 2015) there has been another violent attack of mildew on the grapevines in the Aquitaine region. Up to 60% of wine grapes have been infected on certain parcels and the vice president of the agriculture chamber, Patrick Vasseur, hasn't been underestimating the economic significance this could have since the wine production will evidently be affected. He calls the situation "exceptional" since "even the main branches are affected" Serge Audubert, head of 3 castles in the region and owning a total of 24 ha, has been watching the effects on his land. On his 17 ha of château-laborde grapevines, in Saint-Médard-de-Guizières, 2ha are severly touched. « the leaves, the branches, the grapes, everything is affected. We are going to loose at least 50% of the grapes on these 2 ha. » On the first of may, this vineyard observed a spot on a branch, nothing severe especially since the « Bulletin de santé du végétal » (plant health review) which came out a few days before clearly states that the conditions aren't favorable for contaminations. As a precaution, Serge Audubert starts his preventive treatments on the 7th of may. On the 15th of May, the outburst starts, shocking the entire region: « I have been living here since 1987. I have never seen something like this. Informatics models were supposed to alert us when mildew evolution becomes dangerous. » In winter, Plasmopara viticola is present on dead leaves on the ground as oospores. They are inactive and do not produce any symptoms. When rain falls during spring, these eggs grow and release zoospores when the temperature exceeds 11 degrees. The zoospores will be able to spread and infect the plant's upper tissues through rainwater's splashes. The primary contamination begins by the emission of a filament through the stomatal area where the parasite begins to develop sinkers from which is formed the mycelial network. These sinkers help to feed Plasmopara viticola by stealing the plant's nutrients, which creates discolored and yellowish areas on the it's leaves called “oil stains”. After, on the bottom, conidiophores and conidia are formed. These symptoms cause damages to the leaves’ tissues and affect the plant’s photosynthetic ability, which slows down the maturity of the plant. During the secondary contamination, the conidia are transformed into zoospores that contaminate the surrounding tissues, weakening the plant even more and creating unreparable lesions. Since repairing damaged tissues infected by downy mildew is impossible, the main solutions available to vinyards are preventive solutions, mainly through preventing primary infections. This is mainly done by spraying fungicides on the organs that are most infected: leaves and stems. The most efficient preventive treatment was discovered at the end of the 19th century: a solution made of copper sulfate also known as "Bouillie Bordelaise", the only treatment used until the end of the 20th century. Recently, synthetic fungicides have replaced this chemical treatment and more and more research is being done on alternative eco-friendly preventive treatments The Problem
This year, iGEM Bordeaux’s project is focused on Downy Mildew
In 2015, vineyards are still threatened by the disease
Infection Mode of Downy Mildew