Developing A new Bacteria-based Biocontrol Product against Orobanche Parasitic Weeds. – WeedsBiocontrol

Different approaches will be used throughout the project. Chromatographic approaches (UPLC-DAD-MS / MS) will be used to quantify the production of bacterial metabolites able to inhibit the orobanche growth in the various bacterial solutions we will develop. A qPCR method will also be developed in order to specifically quantify inoculated strains in soils and plants. Methods for analysing the root microbiota by metabarcoding using universal markers (16S rRNA and ITS2) will also be implemented to analyze the impact of bacterial inocula on microbial communities. Finally, the inhibitory activity of bacterial solutions on the growth of orobanches will be evaluated in various in vitro tests mastered by the LEM, then in in planta tests under greenhouse conditions and then in the field.

WeedsBiocontrol aims to offer to farmers and agricultural organizations an eco-responsible solution to biologically protect their crops from Orobanche. Our project is in line with the objectives of the Ecophyto II plan. Pesticides can have various negative effects on, among other things, soil fertility, ecosystem biodiversity, or water quality. The presence of pesticides in food and the environment can lead to negative effects on human health (cancers, neurological effects, respiratory diseases, genetic disorders, for example), as stressed by the media in the case of glyphosate and Roundup ®. There is therefore a strong societal pressure in France and in Europe to develop more sustainable ways to grow crops, and to drastically reduce the use of pesticides.
Our project should make it possible by providing a biocontrol solution against Orobanches.
When developing a biocontrol product, it is necessary to show that the product has no harmful effect on consumers, farmers or local residents; it must not lead to negative effects on the environment; and it must of course show a good efficacy against parasitic plants. These are critical points we will take into account in the WeedsBiocontrol project. We will develop tools (qPCR, metabarcodes) (i) to check, at the end of the culture, the low persistence of our bacterial product in the soil, and (ii) to analyze whether it has or not any impact on soil microbial communities.

Depending on the results obtained, the partners will decide together whether the results should be published in the form of scientific articles or patents. We believe that our technology should move from a TRL4 to a TRL 7 during the project and that it will be possible to offer and market a new Biocontrol product.
A market analysis of bioherbicide products will be conducted at the end of the project to assess whether the product can be brought to the market. The SME BIOVITIS has marketed several products and knows the expected outcomes for selling a new Biopesticide, in technical and legislative terms (marketing authorization dossier). We will assess the countries where to sell the product and the types of additional funding required.

Previous patent: Bally et al. Utilisation d'un acide dicarboxylique pour lutter contre la croissance de plantes holoparasites ou hémiparasites. Published the 21/02/2020.

The WeedsBiocontrol project aims at developing a new biopesticide against parasitic weeds commonly named broomrapes (Orobanche and Phelipanche species), that affects a wide range of crops worldwide. So far, crop protection against parasitic weeds in Europe is mostly based on the use of non-selective chemical pesticides in combination with peculiar plant genotypes of field crops. In line with the governmental French ‘EcoPhyto Plan’ that has the ambition to reduce the use of pesticides and plant protection products in France, environment-friendly ways to protect crops against broomrape must be found. The development of herbicides based on microorganisms and/or natural metabolites from microbial origin and that can target the early steps of parasitic plant development, might contribute to reduce broomrape seed parasitic infestation in agricultural soils. Our lab (LEM) evidenced that several plant-associated rhizobacteria from Azospirillum and Pseudomonas genera are able to produce compound(s) that do not allow the radicle elongation of GR24-treated broomrape seeds, thus stopping the growth of the parasitic plant. The LEM lab discovered that these compounds belong to the dicarboxylic acids family and this discovery was patent published. Furthermore, another natural product released by Pseudomonas strains in their medium was recently discovered in the LEM lab as having a similar inhibition activity against Orobanche. Thus, the general objective of WeedsBiocontrol is to permits the transfer of results and knowledge from the lab (LEM) to the SME BIOVITIS in order to develop a Biocontrol product efficient against Orobanche weeds on rapeseed and sunflower crops. The specific objectives of this proposal are: (i) to design growth conditions of bacteria that enhanced the production of the Orobanche Growth Inhibition (OGI) active natural metabolites and to validate the effect of these enriched-bacterial preparations on broomrape seed germination and/or radicle development through in vitro assays, (ii) to develop a large scale production of the bacterial biocontrol product that will contain the bacteria and will be enriched with OGI natural products, (iii) to evaluate in greenhouse conditions the OGI activity of the biocontrol product by comparing various application methods, product concentrations and timings, and (iv) to evaluate in field experiments the efficacy of the biocontrol product in stopping the growth of the parasitic weed and protecting the targeted crops, mainly rapeseed. Finally, a complete analysis of the feasibility and of the business plan needed for the registration in Europe of a future plant protection product containing the WeedsBiocontrol project’s strain(s) will be realized. This project has thus the potential to offer a relevant environment-friendly solution to protect crops against broomrape parasitic weeds.