Project

Discipline

competitiveness traits; phage-related weapons; insect pathogenicity; cell surface factors; host adaptation; microbial consortia; experimental evolution; comparative genomics; biological pest control; entomopathogenic nematodes; Pseudomonas

Lead
Schadinsekten verursachen grosse Schäden an Wurzeln von Kulturpflanzen. Das Projekt untersucht Möglichkeiten, pflanzennützliche Bakterien mit insektiziden Eigenschaften in Konsortien zu kombinieren, um Schadinsekten zu bekämpfen. Dazu wird ihre Anpassung an das Schadinsekt, funktionelle Diversität und gegenseitige Verträglichkeit erforscht.
Lay summary
Ziele des Forschungsprojekts bei Forschungsbeginn Das Projekt befasst sich mit wurzelbesiedelnden Bakterien der Gruppe Pseudomonas protegens und P. chlororaphis (Pp/Pc), die neben pflanzennützlichen Eigenschaften auch ausgeprägte insektizide Aktivität gegen verschiedene landwirtschaftliche Schadinsekten besitzen. Wir haben bei Pp/Pc Bakterien, trotz deren nahen Verwandschaft, eine erstaunliche Diversität insektizider Eigenschaften, antimikrobieller Waffen (namentlich Bakteriophagen-verwandte Strukturen) und Zelloberflächendekorationen festgestellt. Derzeit ist weitgehenst unklar, welche Rolle die verschiedenartigen Ausstattungen bei der Interaktion mit pflanzenschädlichen Wirtsinsekten und beim Wettbewerb mit Bakterien in und ausserhalb der Pp/Pc Gruppe haben. Dies soll im Projekt mit detaillierten molekularen und funktionellen Analysen untersucht werden. Ausgewählte Pp/Pc Bakterien mit unterschiedlichen Talenten sollen dann in kompatiblen und effizienten Konsortien kombiniert (auch mit weiteren Nützlingen wie insektenpathogenen Nematoden) und ihre Wirksamkeit gegen pflanzenschädliche Insekten getestet werden. Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts Längerfristiges Ziel dieser Grundlagenforschung ist es, möglichst schlagkräftige mikrobielle Konsortien zu erhalten, welche zur biologischen Kontrolle schwierig zu bekämpfender Schadinsekten in der Landwirtschaft eingesetzt werden können, als innovative Alternative zu umstrittenen Pestiziden. Mit Pp/Pc Bakterien gewonnene molekulare, ökologische und evolutionäre Einsichten in Wirts- und interbakterielle Interaktionen sind für verschiedene Forschungsgebiete von Interesse.

Direct link to Lay Summary

Last update: 04.04.2019

Natural persons

Number	Title	Start	Funding scheme

Summary of the research planBackground.Insect pests that attack roots cause great damage to crops and are extremely difficult to target. The use of chemical pesticides will be more and more restricted. Alternative control solutions are urgently needed. Biological control based on plant-beneficial bacteria has great potential for use in agriculture. Pseudomonas protegens and P. chlororaphis (Pp/Pc) are plant-beneficials that stand out as multi-talents. We discovered that Pp/Pc exhibit pronounced toxicity toward plant pest insects on top of their excellent plant-colonizing and disease-suppressive capabilities, which makes them promising candidates for biocontrol. Pp/Pc are equipped with multiple traits that contribute to their plant-beneficial, insecticidal and competitive abilities. Recent evidence points to considerable diversity in equipment and insect interaction of Pp/Pc, which could be exploited to build consortia that combine different talents of strains for superior pest control performance. However, knowledge on insect adaptation and intra- and interspecies competitiveness of Pp/Pc strains and the traits involved is scarce, yet is indispensable for designing compatible and efficient consortia.Overall aim.We will explore the natural insect association of Pp/Pc and their adaptation to insects with the aim to discover new traits that can be exploited for pest control (research line A). Further, we will investigate the weaponry and resistance determinants involved in interbacterial competitiveness of Pp/Pc to create the knowledge needed to ensure compatibility within Pp/Pc-based consortia (research line B). The final aim is to build efficient multi-tasking Pp/Pc consortia and further enhance their efficacy in pest control by including compatible entomopathogenic nematodes (EPN).Project key points.In research line A, we will perform a genome and bioassay based survey of a diverse Pp/Pc strain collection isolated from different hosts to identify molecular patterns relevant for insect interaction. We will explore the adaptation of Pp/Pc to insects in an experimental setup in which model Pp/Pc strains are exposed to pest insect larvae in repeated feeding cycles. Evolved clones will be inspected for genomic changes and alterations in insect interaction. In research line B, we will investigate genomic and molecular features contributing to intra- and interspecific competitiveness within the Pp/Pc collection and model strains, focusing on phage-related weapons and cell surface-exposed resistance determinants. The intention is to define patterns that determine compatibility or incompatibility among Pp/Pc strains. We further aim at gaining insight into the interaction of Pp/Pc with the symbiotic bacteria of EPN in order to improve the compatibility within Pp/Pc-EPN-based interkingdom consortia. We will then use the gained knowledge to build compatible and stable Pp/Pc and Pp/Pc-EPN based consortia and test their efficacy against an agriculturally important root pest under controlled conditions.Expected value.The findings of this project will contribute to answering exciting molecular, ecological and evolutionary questions that are of interest to different research disciplines. We expect to discover novel traits specifying Pseudomonas-insect interactions, which can be exploited for biological pest control. We will provide knowledge on patterns within Pp/Pc that are associated with (i) weaponry and resistance mechanisms involved in intra- and interspecific competition, (ii) insect colonization and killing abilities, and (iii) compatibility with EPN and their symbionts, allowing to build stable multi-tasking pest control consortia. This project will make an important contribution to finding innovative methods for insect pest control. This is highly relevant with regard to current pesticide reduction strategies in Switzerland and Europe.