Changing the System of Seed Health: An initiative of industry and research towards a paradigm shift
A paradigm shift is needed in the whole seed chain to become less dependent or even independent from chemical pesticides which are more and more phased out. The current system of seed health is based on production of pathogen-free seeds by combining the use of fungicide applications in the seed production crops with seed processing technologies. This system guarantees pathogen-free seeds but also can have detrimental effects on non-target organisms including members of the plant and seed microbiome. Reducing the microbiome and its functions by the commonly used physical and chemical disinfection measures results in a less buffered ecosystem of seeds, seedlings and established crops.
To reach the Sustainable Development Goals, robust crops with a high intrinsic resistance against biotic stresses are needed and emissions of pesticides to the environment and residues have to be avoided and replaced by biological low-risk methods.
The project will deliver the proof of concept to the question whether an intact seed microbiome has a positive influence on plant health in the seeds and seedlings and which microbial components play a dominant role in this process. The knowledge is essential to enhance beneficial traits and microbial groups. For seed treatments very limited biological control agents (BCA) are available so far. To be able to study the effects of BCAs as seed treatments on the resilience of the plants a framework consisting of a range of assays for screening and testing new BCAs on seeds will be developed. Individual assays will focus on efficacy against model diseases and pests, crucial ecological characteristics such as shelf life on seeds and relevant economic and regulatory issues. The project will support the seed supply chain to decide on appropriate routes during specific seed production and seed processing steps to implement the paradigm shift needed to ensure seed health and to establish robust crops in emission-free production chains. The project will also have strong impact on science. The provided knowledge on the role of the seed microbiome will be the scientific base to develop methods to steer microbiomes and to develop new BCAs. It will result in new research on microbially buffered seeds and crops. The impact on society will be that major steps towards delivery of robust seeds to agriculture and horticulture will be made to enable the sectors to produce food in a nature-inclusive, circular and economic way.
Knowledge on the role of microbiome and BCAs of seeds and its valorization by seed companies will lead to:
• Development of robust cropping systems that are more resilient to biotic and abiotic stresses
• An increased efficiency in the use of land, energy, fertilizers and other resources needed for circular agriculture
• Reduction of use of chemical crop protection products
• Protection and support of biodiversity
• Reduction of emissions in agriculture and horticulture
• Contribution to develop robust crops resilient to abiotic stresses due to climate change
• Progress in biotechnology including bioinformatics by using genomic information of plants and associated microorganisms
• New tools in the growers’ toolbox to establish robust crops in circular cropping systems
• Production of highly appreciated, healthy and safe food
A paradigm shift is needed in the whole seed chain to become less dependent or even independent from chemical pesticides which are more and more phased out. The current system of seed health is based on production of pathogen-free seeds by combining appropriate production sites with the use of fungicide applications in the crops. During seed processing, applied technologies also aim at clean seeds by combining various measures. Main pillars are methods for physical and chemical disinfection measures including seed treatments with fungicides and insecticides. This system guarantees pathogen-free seeds but also can have detrimental effects on non-target organisms present on and in seeds. Plants and seeds are not organisms existing on their own but are holobionts consisting of the plant together with the plant’s microbiome. Reducing the microbiome and its functions by the commonly used physical and chemical disinfection measures results in less buffered ecosystems of seeds, seedlings and established crops. Saving the seed microbiome can thus result in microbially buffered systems with lower risks for biotic stress in seeds, seedlings and established crops. Since the seed production and seed processing chain is currently aiming at ‘clean’ seeds, a paradigm shift is needed for the entire seed production and processing chain to implement in a disruptive way a system relying on the use of natural biological principles to ensure seed health and quality. The urgency to come to the paradigm shift in the seed supply chain is further increased by the non-renewal of approval of active substances commonly used for chemical seed treatments such as thiram and several neonicotinoids.
In the past decade, the awareness of co-existence and relevance of microbiomes with eukaryotes has increased overwhelmingly. Moreover, the development of DNA and RNA techniques now allows the study of complex microbial populations, including non-culturable organisms, as well as functional traits. Research on relevance of plant microbiomes, especially in the rhizosphere, has exploded. However, the importance of the microbiome associated with seeds is frequently mentioned, but little experimental data are available. There is no information about the effect of storage, processing and treatment of seed on their co-existing microbiome, as well as on the effect for plant growth and health under different conditions. The use of biological control products increases yearly by 15%. Its impact is high in several cropping systems, e.g. in glasshouse crops. However, for seed treatments very limited products are available so far. New scientific approaches and technologies will allow fast, cost-effective and targeted development of new biological control products also for seed treatments.
Understanding the role of seed microbiome
• The proof of concept will deliver an answer to the question whether an intact microbiome has a positive influence on plant health in the seed/seedling stadium and which components play a dominant role in this process.
• Methodology (protocols) to study the microbiome in and on seeds: from composition to function.
• Descriptive data of seed microbiomes in untreated versus sanitized seeds.
• Additionally the functional characteristics of the seed microbiomes that can be linked to seed resilience and seedling health will be determined and used as markers for selection of BCAs.
Biological control on seeds – Development of a framework for screening and testing new agents
• A framework consisting of a range of assays for screening and testing new biological control agents on seeds will become available. Individual assays will focus on efficacy against diseases and pests, crucial ecological characteristics and relevant economic and regulatory issues.
• A fast assay to analyze and predict survival and shelf life of the seed microbiome and applied biologicals will be ready for use.
• The framework for screening and testing of new biological control agents on seeds will be evaluated for model crops and generalized for later use in other crop–target-combinations by seed industries and biocontrol industries.
Dissemination of project results
A paradigm shift is needed in seed production, processing and storage avoiding harming beneficial seed microbiomes. However, there are different routes towards this paradigm shift by preserving, enhancing, steering and adding beneficial microbial communities. The research project will focus on exploration of the role of the seed microbiome, and the pre-competitive development of knowledge needed to exploit the natural seed microbiome and added selected BCAs on seeds. The major impact of the project will be the knowledge transfer needed to support the seed supply chain to decide on appropriate routes during specific seed production and seed processing steps. The impact on science will be the availability of knowledge on the role of the seed microbiome. The impact on society will be the knowledge transfer allowing major steps towards delivery of robust seeds to agriculture and horticulture enabling the sector to produce food in a nature-inclusive, circular and economic way.
General communication with stakeholders will be achieved via annual reports to TKI and contributions to websites and technical journals with information on project objectives and publishable results. An important communication and dissemination channel will be workshops allowing intensive knowledge exchange amongst stakeholders of the seed supply chain and other stakeholders. Results will also be communicated in the international scientific communities during relevant conferences and webinars (estimated 10 oral and 10 poster contributions). Approximately 7 manuscripts for peer-reviewed open access scientific journals and 1 PhD thesis will be submitted for publication.