Targeted microbial manipulations promote crop production and protection
Microbes are important components of the functional biodiversity underlying the flow of plant resources in ecosystems. Understanding this functional biodiversity can point the way to approaches that naturally enhance the sustainability and productivity of Europe’s food and agriculture systems. The EU-funded EcoStack(opens in new window) project set out to ‘stack’ ecosystem services in a synergistic way for maximum effectiveness. The optimisation of functional biodiversity management and the use of bioinspired tools and strategies for pest management can enhance agricultural profitability and environmental protection. Real-world empirical field studies were complemented by modelling and simulation approaches. The latter efficiently addressed the high levels of variability over space and time that are often observed. They also enabled the validation of context-specific, stacked ecosystem services packages for their ecological, economic and social sustainability.
Fungi and bacteria in complex trophic networks
Plant and soil microbiota (microorganisms) provide important ecosystem services to farmers, particularly regarding natural biocontrol of plant pests and disease agents as well as maintenance of soil fertility. “This complex trophic network of interacting holobionts (the host and its associated microbiota) underlies agroecosystem stability and resilience. Understanding these interactions allows the definition of targeted microbial manipulation strategies to enhance plant growth and endogenous defence barriers,” explains project coordinator Francesco Pennacchio of the University of Naples Federico II(opens in new window). EcoStack characterised different strains of two species of fungi – Beauveria and Trichoderma – both naturally occurring and used as biocontrol agents. The team studied their capacity to induce plant growth and defence responses against pathogens and insects under different environmental conditions. The project also identified plant growth-promoting rhizobacteria, isolated from commercial and heritage tomato varieties and primarily belonging to the genera Bacillus and Paenibacillus.
Microbes in multi-level trophic energy flows
EcoStack found an intricate network of trophic interactions spanning the below-ground and above-ground communities. “The soil beneficial microbes studied induce metabolic changes in the plants they colonise, which in turn can influence multiple trophic levels in different ways,” notes Pennacchio. A clear demonstration of the central role of microorganisms in controlling resource dynamics across multiple trophic levels can be seen in beneficial soil fungi that colonise tomato plants. They have a negative impact on moth larvae. EcoStack discovered the mechanism – a disruption of the feeding caterpillar’s gut microbiota which also reduces the immune competence of the pest insect. This latter aspect has the added benefit of favouring the development of insect natural antagonists.
Natural tools for sustainable crop production and protection
“By understanding the mechanisms underlying trophic interactions between microbes, plants, and higher trophic levels, we have been able to design combinations of microbial biocontrol agents showing synergistic interactions and stronger control efficiency,” notes Pennacchio. Moreover, EcoStack used microbe-derived compounds that influence interactions between pests and their natural antagonists to suppress pests and pathogens, harnessing the molecular ‘weapons’ of these organisms rather than the organisms themselves as biocontrol agents. EcoStack has strengthened the knowledge foundation needed to develop efficient and safe nature-based strategies, tools and technologies for sustainable agriculture and demonstrated the potential with targeted microbial manipulations that promote crop production and protection. The project has thus empowered European farmers to maximise ecosystem services to augment crop productivity and farming profitability while enhancing ecosystem stability and resilience. By providing valid alternatives to the use of synthetic pesticides, EcoStack significantly contributes to the ongoing discussion on the Sustainable Pesticide Use Directive(opens in new window) establishing a framework for community action to achieve the sustainable use of pesticides. A new era of sustainable agriculture is on the horizon, leveraging energy flows in trophic networks to benefit farmers, consumers and the environment.
