Maize farming requires high amounts of N fertilizer, with adverse environmental effects and insufficient agronomic sustainability. Certain maize genotypes can be colonized endophytically by atmospheric nitrogen (N2)-fixing bacteria, but the agronomic potential of endophytic N2-fixation is not fully exploited. Our hypothesis is that a scientific understanding of the mechanisms controlling these endophytic N2-fixing associations combined with an assessment of maize genetic diversity and specificity with regards to this interaction could be useful to optimize endophytic N2-fixation and exploit it in agriculture. The aim of the project is thus to better understand the interactions between bacterial endophytes fixing N2 and maize, in order to identify and select maize genotypes that will be able to use the fixed N more efficiently and thus will be less dependent on mineral N fertilization. This will be achieved by developing a multidisciplinary approach integrating molecular physiology, the assessment of whole-plant N responses to the endophytic interaction, molecular plant-microbe ecology and agronomy. We will characterize both at the physiological and molecular levels the atmospheric N2-fixing endophytic interaction using a large-scale integrated transcriptomic, proteomic and metabolomic approach implemented with two established Herbaspirillum and Azospirillum models of N2-fixing endophytic bacteria and 19 representatives of European and American maize genetic diversity. This will allow identifying the genetic and physiological determinants required for an efficient N2-fixing endophytic association. Such study, combined to a genome-scale metabolic modelling approach, will then help obtaining an integrated view on the plant’s response to the endophytic interaction and on its adaptation to temperate climatic conditions. A molecular screening will also be conducted to obtain effective endophytic N2-fixing bacteria for agronomic improvement of maize cultivation at lower N input under temperate pedoclimatic conditions. To this end, we will implement a novel molecular screening strategy, using not only microbial traits but also the plant biological markers of the ability of the plant to utilize the fixed N more efficiently. Production of innovative fertilizers based on inoculant technology will be then undertaken to assess under agronomic conditions, if the maize genotypes exhibiting the best endophytic N2 fixation also exhibit improved performance in terms of biomass and grain production. Such an agronomic evaluation will also be conducted with commercial hybrids known for their high performance under reduced N fertilization. The project focuses on maize, a crop of major economic importance both in France and worldwide. Maize is particularly relevant for this project for four reasons. First, it has a huge genetic diversity, allowing the improvement of both its agronomic and environmental performances in terms of N fertilizer usage. Second, maize is also a model crop particularly suited to perform integrated agronomic, physiological and molecular genetic studies during the whole plant developmental cycle. Third, many maize genotypes are colonized endophytically by N2-fixing bacterial endophytes. Thus, deciphering the relationships between maize physiological status and the provision of “free” N by the bacterial endophytes will deliver science to underpin and implement novel agricultural strategies aimed at reducing the use of N mineral fertilisers in maize farming, which will be facilitated by the industrial development in this project of fertilizer micro-granules serving as carriers for N-fixing endophytic inoculant.

The aim of the FRiPPon project is to explore an emerging class of fungal peptides, called dikaritins, and to understand their role as chemical effectors in fungi interacting with plants. Fungi produce a wide range of secondary metabolites (SMs) acting as chemical effectors to colonize their ecological niche. In particular, phytopathogenic and endophytic species produce SMs to manipulate the physiology of their host or its microbiote. The recently discovered dikaritins are considered as the main class of ribosomally synthesized and post-translationally modified peptides (RiPPs) in Ascomycetes. The first identified dikaritins attracted attention because they are phytotoxins (Ustiloxins, Phomopsins) or effectors manipulating plant immunity (Victorin). Based on the specific features of the biosynthesis of the five dikaritins identified so far i.e. the need for a precursor protein named KEP (Kexin-Processed Protein) and at least one DUF3328 (Domain of unknown function 3328) enzyme for cyclisation, genome mining studies revealed hundreds of dikaritin biosynthetic gene clusters (BGCs) in fungi, in plant pathogenic species but also in beneficial endophytes. In addition, preliminary transcriptomic analyses indicate that some of the dikaritin BGCs are activated in the presence of the host plants which suggests that they play a specific role in these biotic interactions. The specific objectives of the FRiPPon project are: (i) To discover new bioactive dikaritins from fungi interacting with plants, (ii) to explore their chemical diversity, (iii) to characterize their bioactivities in plants and microorganisms, and (iv) to evaluate their potential in agronomic applications. To reach these objectives, the program will focus on a set of four fungal species with well-characterized interactions with plants and high-quality genomic and transcriptomic data: Botrytis cinerea, a polyphagous necrotrophic plant pathogen, Colletotrichum higginsianum, a plant pathogen with contrasting biotrophic and necrotrophic stages on Arabidopsis thaliana, C. tofieldiae, a beneficial root endophyte of A. thaliana and Leptosphaeria maculans a plant pathogen that shows biotrophic, endophytic and necrotrophic stages of infection on rapeseed. Importantly, the project also includes three Penicillium strains that are beneficial for plant growth and show strong agronomic interest for the industrial partner (CMI Roullier). The main challenge of the project is to isolate dikaritins that are weakly (or not) produced in the absence of the plant. To overcome this technical bottleneck, we will carefully identify the BGCs of interest and express them in a heterologous host i.e. yeast. Then, state-of-the-art techniques will be used to extract and purify the dikaritins and to determine their chemical structures. We anticipate obtaining at least five new bioactive dikaritins that will be further tested on plants and microorganisms. In parallel, fungal genetics studies will be conducted to evaluate the role of these chemical effectors in plant-fungal interactions. FRiPPon is a PRCE that draws together two academic institutes, the BIOGER institute (INRAE) and the MNHN, with expertise in fungal-plant interactions and chemical ecology, respectively, and the CMI – Roullier company that develops natural products for the agronomic industry. On an academic level, this interdisciplinary project is expected to help to decipher how fungi manipulate plant hosts or antagonize competitors in their ecological niche, and to reveal new dikaritin chemical structures. Finally, the exploration of this untapped source of fungal SMs will pave the way for the development of sustainable and natural solutions for use in agronomy.

A major challenge of the coming years is to reduce environmental impacts of agriculture while maintaining, if not increasing, crop yields. One solution to reduce fertilizer inputs is to increase the efficiency of crops using them, for example by increasing root growth and resistance to abiotic stresses. Phytostimulants are molecular effectors that when used in small quantities boost plant growth, in particular the root system. Knowing how phytostimulants work in plants could greatly help to use them more rationally, and assess their safety to environment. In any case, this knowledge is frequently asked to obtain marketing authorisation, as for any new agrochemical. The private partner has identified biosourced phytostimulants improving resistance to abiotic stress, root growth, N, S and P contents and increase yields in crops such as rapeseed, pea, soybean and maize. Interestingly, some of these phytostimulants also improve the Arabidopsis root growth in phosphate deficiency condition. The aim of this project is to: 1) Understand how the biosourced phytostimulants improve crop rooting and yields, in particular under abiotic stress; 2) Use these biosourced phytostimulants as new tools to study a multi-stress signalling pathway of Arabidopsis; Through 6 tasks, a private company and two academic partners will collaborate in physiology, genetics, molecular biology, biochemistry, biophysics and metabolomic experiments in order to reach these three aims.

Recognizing the significance of energy efficiency in industry and carbon emissions reduction, FLEXHYON is proposing a clever combination of alternative fully electrified heating systems (microwave, heat pumps, ultrasound) to tackle three specific industrial processes: ultrafast drying of compact material, drying of granular materials and distillation/extraction of ground material to address their urgent need to transition from fossil energy to renewable and low-carbon energy sources. Three optimized prototypes will be built and demonstrated in 3 industrial environments: ceramics, feed production, biomass. The quality and economic impact of the developments will be evaluated using LCA and LCC; environmental and technical performances, health protection, safety will be demonstrated and validated. Sound market strategies will be developed, giving clear indications on scalability, transferability and replicability across different industrial sectors, commercialization and deployment will be achieved through development and validation of set of business models for the 3 business cases. The FLEXHYON solutions will exhibit significantly higher energy efficiency in comparison to traditional fossil fuel-based heating technologies, therefore leading to a reduction in GHG emissions, maximizing primary energy savings, and enabling higher production flexibility (e.g. production on-demand, production on-site). Their scalability (upscaling, downscaling) will allow to better follow market demand and enable leaner production paradigms. To achieve the project goals, FLEXHYON combines 9 partners covering the whole technical value chain required for the development and validation of alternative fully electrified heating systems. The Consortium will also implement different dissemination and communication activities to raise awareness about the benefits of alternative heating systems in industry and exploitation opportunities from know-how generated and exploitable results developed.

CIRCULAR BIOCARBON is a first-of-its-kind flagship biorefinery conceived to valorise organic fraction of municipal solid waste (OFMSW) into value-added products: diamond-like-carbon coatings, green graphene, tailor-made bio-based fertilisers, or bio-plastic, as well as a variety of intermediate products. In order to maximise replicability and boost potential penetration in the market, the biorefinery will be operated for three years in Spain and Italy, and consistent business and exploitation strategies will be put in place. The CIRCULAR BIOCARBON biorefinery, organised through a pool of cascading technologies, start from anaerobic process steps (after proper pretreatment) of mixed urban waste streams, of which OFMSW is the main one, in order to treat all the biowaste produced by a medium-size city (at the end of the project, a commercial scale biorefinery will be fully operative). The fundamental objective of the CIRCULAR BIOCARBON project is to open up new business frameworks based on a new circular vision of waste treatment in a city towards a sustainable bioeconomy, to which actors leading the territorial waste management schemes and policies will be brought to maximize impact on the market, on policy makers and on society.