Stilbenoids as promising environment-friendly natural products to minimize the contamination of wheat and grape with toxigenic fungi and associated mycotoxins – StilDeTox

The project StilDeTox is driven by the necessity to develop efficient and sustainable solution to manage the mycotoxin risk in the cereal and wine sectors and guarantee the safety of cereal and grape-derived products. The promising potential of vine by-products as a source of bioactive compounds and more specifically of bioactive silbenoid extracts will be investigated to identify efficient antifungal and anti-mycotoxin natural solutions. To achieve its goal, StilDeTox will implement a strategy combining basic and applied studies. StilDeTox will establish new scientific knowledge to fill in the gaps that currently dampen (i) the screening and the optimization of efficacy of silbenoid extracts to counteract toxigenic fungi and (ii) the transfer of lab-scale results to the field or the vineyard. Applied studies will focus on a small set of stilbenoid solutions identified as the most promising candidates by the consortium. They will consist in defining the best formulation, developing a pilot production procedure, testing and validating the formulated solutions using small-scale prototypes in laboratories and simulated controlled environment.

StilDeTox’s expected results can be divided in three levels. (1) The proposal will deliver original and central knowledge on the phytochemistry of stilbenoids in vine by-products (different parts of vine from different genetic origins), on the ability of this class of phenolic compounds to counteract the fungal growth and production of mycotoxin by two pathogens of major concern in the European agriculture sector and on the fungal metabolic pathways that stilbenoids can impair. (2) The proposal will deliver STEs with confirmed ability to efficiently and significantly challenge deoxynivalenol and ochratoxin A contamination. (3) The project will deliver two pre-commercial environment-friendly plant care products with an efficacy demonstrated in operational situations, a plant care product targeting F. graminearum and its production of deoxynivalenol to be used in the cereal sector and a plant care product targeting A. carbonarius and its production of ochratoxin A to minimize the contamination of grapes.

Biocontrol strategies are key strategies that the cereal and wine industries intend to develop as part of the Ministry of Agriculture's EcoPhyto strategic plan to produce more and better. The project will thus contribute to the development of alternative solutions for these two major sectors in France. The results of StilDeTox will allow the development of environmentally friendly solutions by valorizing co-products from the wine sector.

Significant results will be presented in international conferences and will be published in peer-reviewed journals.

Phytopathogenic fungi are among the dominant causal agents of crop diseases. In addition to direct losses related to yield reduction, some fungi produce mycotoxins harmful to humans and animals. In Europe, cereals and grapevine are the most concerned crops. The deoxynivalenol mycotoxin producer, Fusarium graminearum, and the ochratoxin A producer, Aspergillus carbonarius, are the most frequently found in cereal and grape crops, respectively.
Although good cultural practices have been proposed to minimize the contamination of wheat with deoxynivalenol and of grape berries with ochratoxin, they are not sufficient to guarantee the compliance of harvests with the EU regulations. Combined with tillage, crop rotation and cultivar choice for wheat, the use of fungicide is a key factor in the integrated management strategies aiming at controlling mycotoxins. However, according to the growing commitment of European and National governments for limiting chemical inputs, biocontrol is a promising solution to be used instead of or in complement to chemical treatments. The French National Ecophyto plan claims to gradually reduce chemical treatments, hence stimulating the development and use of all novel practices including biocontrol. The future of agriculture will require the development of new environmental-friendly agronomical strategies guaranteeing the safety of food and feed. Among these strategies, the development of products issued from natural sources to protect crops against fungal pathogens and their mycotoxin production will contribute to decrease the use of chemical fungicides. In this context, the goal of StilDeTox is to characterize natural stilbenoid extracts (STEs) from vine by-products to be used in integrative fungal/mycotoxin control strategies. The project is organized in three tasks and will implement an integrated approach, from the production and screening of the STEs (task 1), the elucidation of the mechanisms of action (task 2) to the assessment of the in planta efficiency of formulated solutions and optimization of the production process (task 3). Environmental preoccupations will drive the project: identification of alternatives to chemical fungicides, zero-solvent extraction procedures, valorization of grapevine by-products.
To achieve these objectives, StilDeTox associate three academic and one private partners selected for the diverse and complementary expertise and skills that they collectively bring into the project. The three academic partners are INRA, UR 1264 MycSA, which research programs focus on the understanding of the regulation of toxin biosynthesis by fungi, UR Oenology EA 4577, USC 1366 INRA, MIB which research programs target the isolation, characterization and evaluation of biological activities of phenolic compounds from grapevine/wine and, INRA, UMR 1065 SAVE specialized in developing integrated and sustainable protection strategies of the vine. The private partner is BioLaffort company which has expertise in plant product extraction and vegetal protection.
The first innovation of StilDeTox lies in its guiding challenge using vine-production waste to address significant public health and economic issues. StilDeTox will develop innovative methodologies starting from the recycling of vine industry by-products using ecological technologies and ending with the proposition of biofungicide formulations. A second major innovation lies in the multidisciplinary and transdisciplinary approach that will be implemented. Basic studies and applied approaches will be combined, allowed by the complementarity of the expertise gathered in the project’s consortium.