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14th – 19th August 2022
ISME is the largest symposium on microbial ecology in the world and is normally organised every 2 years. The last ISME meeting was cancelled due the pandemic, which resulted in this 2022 meeting becoming even larger than it would normally be. The meeting was attended by over 2,000 attendees who over the course of 5 days had the opportunity to present and discuss the latest research in microbial ecology: from human gut, marine, plant and soil microbiome, to newly discovered species, origins and limits of life, microbial evolution, molecular microbe-microbe interactions and many, many more. Every day we had an almost impossible task to choose between eight concurrent talks, interspersed with breaks to view over 400 posters per day. My main interests were advances of sustainable food production, with particular focus on beneficial and biocontrol microbial communities which were covered in plant / soil microbiome and microbe-microbe interactions sessions.
Highlights from plant microbiome sessions include a talk by R. Berendsen (Utrecht University) who reported the Arabidopsis downy mildew (Hpa) isolates of distinct origin maintained in separate labs in Netherlands and Germany were associated with nearly isogenic Xanthomonas strains which reduced Hpa spore production. This indicates that by way of Hpa passaging the plants have co-evolved their microbiome to reduce the impact of pathogen. This microbiome evolution could provide new source of biocontrol organisms. Similarly, C.M. Vogel (ETH, Zurich) used inoculation of Arabidopsis with 136 random bacterial synthetic communities followed by pathogen infection and machine learning to identify protective strain combinations. This powerful new framework could identify and predict community size and composition required for optimal disease suppression. Molecular mechanisms of microbiome recruitment have been addressed by many talks and posters. Notably, J. Jose (Friedrich Schiller University) used random mutant screen in Arabidopsis to identify candidate genes responsible for microbiome recruitment, and S. Pfeilmeier (ETH, Zurich) presented work on the effect of NADPH oxidase RBOHD mutants on microbiome homeostasis, plant-microbiome dysbiosis and the virulence of opportunistic pathogens. Such studies are paving the way towards better understanding of how genetics shape the microbiome and will be crucial for breeding new crop varieties with enhanced microbiome. The effect of transmission of microbiome from conspecific (from the same species) or heterospecific (from different species) source on the microbiome evolution was investigated by K. Meyer (UC – Berkeley) showing that host’s neighbourhood can drive divergent microbiome evolution. This is important when strategies such as multi species intercropping, wild flower borders and cover crop strategies are considered.
Most notable talks from the soil microbiome research were by A. Jousett (Nanjing Agricultural University, China) and K. Schlaeppi (University of Basel). A. Jousett proposed new approach based on trophic and non-trophic ecological networks in soil microbial communities to predict the suppressiveness of microbiomes to soil borne diseases. This view shifts away from the use of a few biocontrol strains that normally fail to establish or provide disease control, towards understanding the robustness or microbial networks against pathogen invasion and their ability to suppress pathogens. It requires the study of resource competition and antibiosis within microbial community and can highlight potential weak points in community that could be the focus of microbiome engineering for sustainable and long lasting soil disease suppression. K. Schlaeppi on the other hand presented one of the first studies on how plants with and without benzoxainoid root exudates structure soil microbiome which in turn affects plant performance and disease susceptibility of the plants in the next cropping cycle. Interestingly the effects were dependant on soil type, fertility and soil microbiome (positive in one field but negative on the other) and also the plant host genotype in the following generation. This again highlights the importance of host genetic factors shaping microbial communities and the need to include them in the breeding programmes to capitalise from better utilisation of native microbiomes. Other soil microbiome highlights included the fact that i) protist predators play much more important role in soil microbiome turnover than previously though (S. Geisen, Wageningen University); ii) that domestication significantly altered nitrogen fixation and methane production functions of rice roots associated microbiome (J. Chang, Chinese Academy of Sciences); and iii) that soil fungal networks actively disperse bacteria and phages across soil pores and chemical gradients otherwise unbridgeable and thus influencing soil bacterial communities (L. Y. Wick, Helmholtz Centre for Environmental Research).
Other highlights from the meeting include round table discussions on the use of microbiome in sustainable food production, and networking, social and outreach events organised in parallel. Organisation of the meeting was excellent, which was helped by great weather, a fabulous location on the shore of the Lake Geneva (Lac Léman) and ample supply of food and drinks including locally grown wine.
Matevz Papp-Rupar, NIAB East Malling, UK
TOP IMAGE: The front half of the enormous plenary lecture theatre able to sit over 3000 people
View of the Lausanne across Lake Geneva just 15 min walk from the conference centre.
These conference reports are written by the beneficiaries of our travel fund.
Click here to read more about the fund and apply yourself
