Food safety is a major issue in France and in the world. In this respect, much attention requires to be paid to the possible contamination of food and feed by fungi and the risk of mycotoxin production. Mycotoxins are frequent contaminants of cereal. According to survey data published by ONU, 25 % of the world crops are contaminated. Most mycotoxins are not degraded by the common technological treatments and thus remain present in finished products. Thus, mycotoxins contamination is a significant problem of food safety throughout the food chain. The control of the mycotoxins contamination represents a major challenge for the wheat sector (soft wheat and hard wheat). These are the fungi of the Fusarium genus and the associated production of trichothecenes (with deoxynivalenol or DON as the main contaminant) that are, due to their potential toxicity and their occurrence, the most worrying contaminants. The wheat contamination by mycotoxins is particular complex for at least two reasons i) different fungal species contaminate simultaneously wheat grains and ii) these fungi produce concurrently several trichothecenes. The aim of the DON&Co project is to answer the question "how the composition of the Fusarium community influences the concentration and the type of trichothecenes accumulated in the grain and, as a consequence, its toxicity?" The DON & Co project will lead to the definition of agronomic tools allowing the respect of current European regulations/recommendation (EC N 1881/2006 and 2006/L229) but also to the acquisition of reference data concerning the toxicity of DON and its acetylated derivates. These references will lead to a better appreciation of the "mycotoxin risk" in wheat and could contribute to the evolution of regulations. Only an integrated approach, such as the one proposed in the project DON & Co, combining descriptive studies, epidemiological analysis (from the flora to the toxins) with mechanistic approaches, will allow answering the proposed question.