Team:Toulouse/ethics

The ethical questioning turned out to be one of the major starting points of our project. Acting on an established environment and modifying it is no mean feat and our thinking combines technical and philosophical point of views. The actual purpose of our project also leads us to undertake an ethical questioning about the role of the scientist regarding “useless” things such as the trees lining the Canal du Midi.

Protection of the beauty

Is it the scientists’ role to protect beauty?

Beauty is a feeling of satisfaction and is selfless. It is more a feeling than the property of a thing, this is not a notion we can clearly understand. Indeed, we can find something beautiful even when we don’t know the purpose of the object. There is always a distinction between natural beauty and artistic beauty according to Hegel, the famous author. The artistic beauty is born from our mind and our spirit: it is an element of signification of the work of art whereas the natural beauty of the object is external. In a way, the Canal du Midi combines both types of beauty: a natural one regarding the nature, the centenary plane trees but also an artistic one since the Canal was built by the human hands. Usually, scientists judge beauty as a superficial feature not deserving to undertake any kind of scientific efforts to maintain it. The traditional role of scientists is to solve global issues and to elaborate complex strategies in order to find useful solutions for everyone’s life. Once made this observation, one may wonder why synthetic biology would be used only to protect the useless beauty of a local heritage such as the trees lining the Canal du Midi.

This crucial interrogation leads us to consider science and synthetic biology in another way. What if the role of scientists was also to make people rediscovering the beauty of nature? What if the bases of new scientific challenges resulted from a more local scale? Science does not have to be elitist, it has so much to gain opening itself to these challenges. First scientifically, as research is never useless and as we never know the impact and the scope of our results. Then, socially as we could measure the deep interest raised by our project within the population and the media. Adopting a new vision of synthetic biology, we probably make people change their mind about this innovative discipline. The traditional cold objectivity of science distances itself from the society. Scientists are also beings capable of feeling the beauty, sensitive to the charm of landscapes and able to understand the usefulness of useless trees … The design of a strategy to protect useless beauty may seem senseless but we believe that it is also the scientist’s duty. Thus, it becomes essential to protect the beauty of this site.

Human intervention in the nature

The main question would be to understand the purpose of taking actions in nature. Does the mankind have the proper right to operate in nature?

The nature

The nature is known as a creation of God. Thus, human is linked to the nature and for that reason the nature deserves to be respected and loved. The nature is also a source of life: indeed a man needs to breath, drink, eat. If he is deprived of these elements, he would die. Therefore, human survival depends on the nature. Everything we eat comes for the environment: vegetables, cereals, meat, fish. Even if everything has an origin in the nature, men have always taken action in the improvement of the natural species of food.

The nature is a source of wealth for the mankind. It ensures survival and development by giving men the wood, the rocks, the soil to build shelters. All these resources allow human to develop their civilization. Besides that, the nature as resources and has more relationship with men. One functional relationship: the nature is a source of education. By observing it, the mankind has made major discoveries: animals show us some examples of social life attitudes and successful technics. And an emotional relationship: being in contact with nature can allow men to feel strong emotion, as describe by poets like Hugo and Lamartine.

The major important aspect is to be aware of the importance of the nature in the mankind’s life. By destroying and hammering the nature, we jeopardize our lives. We need the nature, we come from the nature and we depend on nature for our survival, our food, our discoveries and our civilisation. Thus, respecting, loving and preserving the environment is a question of survival.

Impact of mankind

Since the birth of humanity, men modified their environment, changing it for their own comfort and profit depending on their own desire.By increasing the spatial development, humans modify the natural environment. However, they become aware of the risks for the planet and start restoring what they previously transformed. But how have men modified the environment? How can they preserved the natural balance?

It is true mankind can have harmful actions for the nature and the environment such as the waste discharge, oil slicks, intensive fishing but also the introduction of devastating species such as the pathogen, Ceratocystis platani.

For decades, mankind realized that all its modifications treat humanity and the nature as a resource. Thanks to this understanding, a new desire was born, a wish to protect the nature and the wildness. Men want to protect and preserve the nature: they want to limit the results of human actions. Man fits with his position: he takes advantage of the environment and the environment takes advantage of the reasoned human interventions. There is an adaptation of the mankind toward the nature.

Moreover, humans have the capacity of empathy: people are able to understand the emotions and cognitive states of other organisms and to identify to them. To respond to these feelings, humans have technological tools allowing them to fight against enemies such as Ceratocystis platani.

Natural and artificial

Talking about the nature refers to the whole world with an exception: all the transformations made by mankind. Thus, the nature consists in the real without all the artificial elements created by humans. The nature is existing regardless of men and his interventions whereas artificial is everything that exists thanks to humans. However, pretending that natural and artificial are opposite does not seem to be true. Indeed, when a man creates something it becomes possible to discover naturel elements. Man cannot create without elements provided by the nature, he is just transforming the nature, changing the shape.

Men already changed nature: they are surrounded by animals and plants which are not wild anymore. So can we still consider them as natural? They come from human wishes and not from natural selection, so what is the limit between natural and artificial? An important aspect for us is the ability to think about the involvements of their choice regarding changes in environment for example in our project.

By all means, the natural world and its organization would be drastically changed to reduce the different kind of pain that the organisms can feel such as the infection of Ceratocystis platani with the plane trees. Indeed, promoting the idea that even non-human organisms pain in the nature is a serious ethical problem becomes a major goal to be taken care of. Furthermore, cancer, depression, malaria are natural results of evolutive processes that we consider to be life threatening and we need to fight. Why would it not be the same for our plane trees? It becomes ethicaly intolerable to realize the cruelty of the nature for the plants and our purpose is to encourage people to realize this.

Of course, men are responsible for their mistakes such as the introduction of Ceratocytis platani and should fix it by any way. But is it too stupid to think that nature will respond to this threat? Since ages nature was able to keep its balance, if one specie dies another takes the place. So if all plane-trees die by this disease, there will be another species which will be able to take up this ecological niche. This project just shows the wish of humanity to interfere in the nature.

SubtiTree

SubtiTree will live in sap tree, thus we use one endophyte Bacillus subtilis strain. In order to contain our bacteria in this area during a short period of time, we modified some of its survival characteristics. First of all, the control of synthetic bacterium location concerned us,that is why we border it inside the plane tree. Sap tree is known to contain a certain quantity of proline which could allow bacterial growth whereas the soil is composed by only trace of this amino acid. Thus, we decided to delete the proline production pathway to make an auxotrophic bacterium for this amino acid.

Secondly, SubtiTree is conceived as an annual bacterium to avoid any kind of mutations. It is known that endophyte bacteria must sporulate to survive to winter. Thus, we chose a B.subtilis strain without late genes of sporulation. So SubtiTree is a non-sporing bacterium, which means that under stress conditions (cold temperature, food lack …) or outside the sap, the bacterium will not resist and die.

These two characteristics of SubtiTree show that it is an annual bacterium, which can only grow in sap tree. By combinind them, they prevent any long term colonization of an ecological niche by SubtiTree against wild type bacteria. These prevent a long term effect.

While we were trying to respond to bacterial spreading problem, at the same time we wondered about horizontal gene transfer. The transmission of genes from our synthetic bacterium to wild type bacteria could be blocked with two modifications. First, as used in genetic engineering, plasmids are a tremendous way to transfer some genic information. In this way, it is not the best way to restrict the collecting transgenic DNA. That is why we inserted our genes in the bacterium chromosome.

Secondly, some bacteria are able to accept chromosomal DNA, like Bacillus subtilis. Thus, the previous strategy is not efficient enough to prevent transfer. We could include the toxin/anti-toxin system. The toxin gene is near our synthetic gene, contrary to the anti-toxin gene. So if there is a transfer of our synthetic gene, the toxin gene will be included in the transfer. Receiver bacteria will die by the production of the toxic protein.

Our synthetic genes are not the only problem in the design of SubtiTree. One of the side effects of our cloning method is the persistence of antibiotic resistance genes. This is incompatible with the introduction of SubtiTree in the environment. It is possible to delete this resistance in chromosome. To conclude, the spreading limitation shown previously makes the use of SubtiTree acceptable in the environment.

Public perception

Thanks to the bolts we used in SubtiTree construction, its application interest civil services. Indeed some city halls and regional councils supported our local engagement. Beyond that, our project interests the highest level of the “Canal du Midi” administration: the national navigation authority and the Ministry of agriculture funded this project. They are still interested in continuing this work after the iGEM competition.

This project also received the attention of the public through several articles in newspapers, television, radio and internet. First we had just a local coverage, but days after days there were some national media coming to us. This coverage media allowed us to have contact with regular people and thanks to that they participated in the development of this project. This interaction with the public allowed us to develop the safety matter of our project. The support they gave us is the result of the scientific popularization of our project.

One single tree infected by the canker, that is a perimeter of a couple of hundred meters which is included in the prophylactic cut. So there a healthy population in this area, we want to protect this tree. There is a common principle in agronomics that said that you prefer to save the population to the subject. According to this concept the introduction of our GEM seems acceptable. A result of the subtitree’s introduction is the modification of endophytic microbial fauna, but without any treatment organisation of the entire population will be messier. As subtitree is an annual bacterium, its side effect will not last in the time, this disruption in this balance will return to the normal.

Furthermore, usual fungicides used come from chemical industry. They contain chlorine atom and aromatic hydrocarbon, so their remediation is complicated and they represent a source of pollution. We propose to use in this project biofungicide, so they are eco-friendly and more specific. Thus they seem to be a good way to fight against the fungal infection.

Feasability

We wonder about the feasibility of tree’s treatment. As we used endophytic bacteria, we can count on the natural growth of SubtiTree inside the sap. So we can inject few bacteria to be sure to have enough bacteria to protect the tree. Some researchers already inject bacillus subtilis strain in plants and observe an increase of bacteria concentration to a maximum of 105 bacteria/mL.

As we inject a poor quantity of bacteria, the injection remains cheaper than the injection of several litter of fungicide. Plus this injection prevents the cutting of trees, which is very expensive. Cutting one tree cost around 3 K€. The administration in charge of the protection of the “Canal du Midi” already plans to spend 220 million euros to cut and replant all trees along the Canal. Besides the important cost of cutting tree, it will destroy one of the symbols of south-west of France.

We know that SubtiTree could be improve in many ways, but in the iGEM’s circumstances we could not have the time to go deeper. First, we can improve the fixation module. Using chitin as fixation anchor is simple but not enough specific to fix just one fungus type. That’s why we first think to fix SubtiTree to one protein included in the Ceratocystis platani’s membrane: CP.