insect pests; plant beneficial nematodes; biocontrol bacteria; soilborne diseases; fluorescent proteins; disease resistant soils; insecticidal activity; biosensor bacteria; antifungal activity; wheat production; molecular; soil health; disease suppressive pseudomonads; Soil bacteria
Dennert Francesca, Imperiali Nicola, Staub Cornelia, Schneider Jana, Laessle Titouan, Zhang Tao, Wittwer Raphaël, van der Heijden Marcel G A, Smits Theo H M, Schlaeppi Klaus, Keel Christoph, Maurhofer Monika (2018), Conservation tillage and organic farming induce minor variations in Pseudomonas abundance, their antimicrobial function and soil disease resistance, in FEMS Microbiology Ecology
, 94(8), fiy075.
Imperiali Nicola, Chiriboga Xavier, Schläppi Klaus, Fesselet Marie, Villacrés Daniela, Mascher Fabio, Jaffuel Geoffrey, Bender Franz, Dennert F, Blanco-Pérez R, Van der Heijden Marcel, Maurhofer Monika, Turlings Ted, Keel Christoph, Campos-Herrera Raquel (2017), Combined field inoculations of Pseudomonas bacteria, arbuscular mycorrhizal fungi and entomopathogenic nematodes and their effects on wheat performance, in Frontiers in Plant Science
, 8, 1809.
Imperiali Nicola, Dennert Francesca, Laessle T, Velatta C, Fesselet Marie, Mascher Fabio, Mavrodi Olga, Mavrodi Dmitri, Maurhofer Monika, Keel Christoph (2017), Relationships between root pathogen resistance, abundance and expression of Pseudomonas antimicrobial genes, and soil properties in representative Swiss agricultural soils, in Frontiers in Plant Science
, 8, 427.
Bensidhoum Leila, Nabti Elhafid, Tablil Nassira, Kupferschmied Peter, Weiss Angelo, Rothballer Michael, Schmied Michael, Keel Christoph, Hartmann Anton (2016), Heavy metal tolerant Pseudomonas protegens isolates from agricultural well water in northeastern Algeria with plant growth promoting, insecticidal and antifungal activities, in European Journal of Soil Biology
, 75, 38-46.
Keel Christoph (2016), A look into the toolbox of multi-talents: Insect pathogenicity determinants of plant-beneficial pseudomonads, in Environmental Microbiology
Dennert Francesca, Imperiali Nicola, Mavrodi Olga, MKavrodi Dmitri, Mäder Paul, Mascher Fabio, Maurhofer Monika, Keel Christoph (2016), Abundance of plant beneficial pseudomonads in the rhizosphere of winter wheat grown in different agricultural management systems, in Bardin M, Köhl J (ed.), IOBC WPRS Bulletin, Germany, 144-147.
Fesselet Marie (2016), Die Bodenbiologie bringt Landwirte und Wissenschaftler zusammen, in Agrarforschung Schweiz
, 7, 156.
Venturi Vittoria, Keel Christoph (2016), Signaling in the rhizosphere., in Trends in Plant Science
, 21, 187-198.
Mysko Larissa (2015), Survival of Pseudomonas protegens CHA0-rif in combination with nematodes and mycorrhizal fungi under field conditions
, Bachelor thesis in Agricultural Science, ETH Zurich.
Wyler Michele (2014), Abundance of fluorescent pseudomonads in Swiss agricultural soils
, BSc thesis in Agricultural Sciences, ETH Zürich.
Staub Cornelia (2014), Influence of management practices on abundance of plant beneficial pseudomonads.
, Bachelor thesis in Agricultural Science, ETH Zurich.
Soil health is of utmost importance for reliable high quality crop production. In Switzerland, as elsewhere, soil diseases and pests cause significant crop losses every year. Soil-dwelling fungal pathogens and insect pests, the main causal agents, are extremely difficult to control with conventional methods. Beneficial soil bacteria colonizing plant roots are well known as natural antagonists of soilborne diseases and promoters of soil health, in particular those belonging to the genus Pseudomonas. Since Swiss policies are increasingly promoting environment-friendly farming, it is of major interest to find ways to enhance the abundance and activity of natural populations of such biocontrol bacteria and to exploit their potential as soil additives for improving soil health.To advance knowledge on how to promote and sustain natural populations of beneficial bacteria, the first main objective of this project is to do a survey of pseudomonads harbouring plant-beneficial traits, i.e. antifungal and anti-insect activities, in representative Swiss agricultural soils used for cereal production and to investigate within the frame of five on-going long-term field trials performed by Agroscope ACW Changins, Agroscope ART Reckenholz and the Research Institute of Organic Agriculture (FiBL) the impact of agricultural practices on the abundance and expression of these key traits involved in soil health. Abundance of plant-beneficial traits will be investigated using a quantitative PCR approach based on relevant plant-beneficial genes, i.e. in particular those required for the control of fungal diseases and insect pests. The ability of soils to sustain the expression of these plant-beneficial Pseudomonas traits will be studied using biosensor strains carrying autofluorescent protein-based reporter fusions. In addition, a metagenomic analysis of the investigated soils will be performed in collaboration with the project B. Duffy/T. Smits which will provide information on the diversity of the plant-beneficial pseudomonads present in the soils. Data on abundance and activity of biocontrol pseudomonads and their plant-beneficial traits and on their diversity will be related to data on the susceptibility/resistance of individual soils to soilborne diseases, with the aim to generate bio-indicator tools for monitoring soil health. Data will also be linked to bio-indicator data generated for pest-suppressing nematodes by the project of T. Turlings/M. Mascher and for arbuscular mycorrhizal fungi by the project of M. van der Heijden/F. Oehl/C. Wagg who will investigate the same field sites.The second main objective is to take novel approaches for improving soil health by (i) application of select plant-beneficial pseudomonads with activity against both plant-deleterious fungi and insects, and (ii) by using optimal combinations of plant-beneficial bacteria and nematodes (in collaboration with the Turlings/Mascher project) to control soilborne diseases and pests. The third main objective of the present project will be to perform field trials together with the Turlings/Mascher and the van der Heijden/ Oehl/CWagg projects. In these field trials, we will investigate the effect of different microbial inoculants (disease and pest-suppressing pseudomonads, pest-suppressing nematodes and arbuscular mycorrhizal fungi), either alone or in combination, on the health and the performance of wheat. Research activities will focus on wheat-oriented cropping since wheat is the most important field crop and an important source of income for farmers. Wheat was produced on about 80’000 ha in 2010 in Switzerland, representing over 50% of the field surface, and domestic wheat production provides almost 80% of the wheat used for bread preparation.This project will provide important information (i) on the ability of representative Swiss agricultural soils to accumulate plant-beneficial pseudomonads and to sustain their activity, and (ii) on how cropping methods can be adapted to increase the soil’s own natural resistance to diseases and pests, a knowledge which is highly valuable to Swiss farmers and to any institution connected to agriculture and field crop production. If the project is successful, new biocontrol formulations and combinations of pseudomonads and nematodes for environmentally-sound plant protection will be established, which can then, in collaboration with biocontrol companies, be developed as new biocontrol product(s) to the benefit of Swiss farmers, gardeners and consumers. The research efforts taken by the present and the collaborating projects will most certainly reveal novel ways to sustain and possibly to further increase crop productivity and quality to the benefit of Swiss agriculture, without harming the environment.