Reporting of Pseudomonas syringae in non-agricultural habitats

We have reported that a major part of the global P. syringae meta-population is in non-agricultural habitats, particularly freshwater habitats. The distribution of P. syringae across these habitats and the genetic relatedness of strains led us to specify how the life history of this bacterium is linked to the water cycle. Among the reservoirs of P. syringae we identified that leaf litter in sub-alpine zones harbored large populations of P. syringae that are transferred to snowpack during the winter and where the bacterium survives until snow melt. Melt water carries the bacterium through the soil where it feeds into the ground water and eventually is transferred to river water that further disseminates the bacterium and is also used for irrigation.

Monteil, C.(2011). Écologie de Pseudomonas syringae dans un bassin versant : vers un modèle de transfert : des habitats naturels aux agro-systèmes. Thèse Université d'Avignon. https://hal.inrae.fr/tel-00916593v1 Monteil, C., Guilbaud, C., Glaux, C., Lafolie, F., Soubeyrand, S., Morris, C. 2012. Emigration of the plant pathogen Pseudomonas syringae from leaf litter contributes to its population dynamics in alpine snowpack. Environmental Microbiology, 14, 2099-2112. DOI : 10.1111/j.1462-2920.2011.02680.x https://hal.inrae.fr/hal-01318703v1 Monteil, C., Lafolie, F., Laurent, J., Clement, J.-C., Simler, R., Travi, Y., Morris, C. 2014. Soil water flow is a source of the plant pathogen Pseudomonas syringae in subalpine headwaters. Environmental Microbiology, 16, 2038-2052. DOI : 10.1111/1462-2920.12296 https://hal.inrae.fr/hal-01688240v1 Morris, C., Monteil, C., Berge, O. 2013. The life history of Pseudomonas syringae: linking agriculture to earth system processes. Annual Review of Phytopathology, 51, 85-104 DOI : 10.1146/annurev-phyto-082712-102402 https://hal.inrae.fr/hal-02652198v1

Genetic diversity of environmental strains of Pseudomonas syringae

Within the large genetic diversity of P. syringae isolated from snowpack and river water, we found effector alleles different from those harboured by strains isolated during epidemics on tomato and kiwi. The environmental strains were nevertheless pathogenic to tomato and kiwi and also had relatively broad host ranges. Because the strains from snowpack and river water were phylogenetically very closely related to those from epidemics, this work showed that crop pathogens may have evolved through a small number of evolutionary events from less aggressive ancestors with a wider host range that are present in non-agricultural environments. A series of stochastic events could lead to the encounter of strains from non-agricultural environments with cultivated plants and to their eventual emergence in disease epidemics. Our work has contributed to the availability of whole genome sequences of strains from non-agricultural habitats currently used in studies of pathogen evolution.

Monteil, C.L., Cai, R.M., Liu, H.J., Llontop, M.E.M., Leman, S., Studholme, D.J., Morris, C.E., and Vinatzer, B.A. 2013. Nonagricultural reservoirs contribute to emergence and evolution of Pseudomonas syringae crop pathogens. New Phytologist, 199, 800-811. DOI : 10.1111/nph.12316 https://hal.inrae.fr/hal-02648548v1 Morris, C. E., Lamichhane, J. R., Nikolic, I., Stanković, S., Moury, B. (2019). The overlapping continuum of host range among strains in the Pseudomonas syringae complex. Phytopathology Research, 1:4, 16 p. DOI: 10.1186/s42483-018-0010-6 https://hal.inrae.fr/hal-02621367

Effet de Pseudomonas syringae sur les précipitations

Because of the efficient ice nucleation activity of P. syringae at relatively warm temperatures, its dissemination with the water cycle - and particularly the feedback cycle between plants and clouds – has important implications for beneficial effects on rainfall. We have been leading an international interdisciplinary network to elucidate the settings for and extent of this beneficial impact using various social media and shareware tools. Through this work we have brought the idea of bioprecipitation into the realm of very plausible. Bioprecipitation, a feedback cycle between plants and clouds wherein rainfall is induced by ice nucleation active microorganisms from plants, is now an object of expanding research activity worldwide.

Aho K., Weber C., Christner B., Vinatzer B., Morris C.E., Joyce R., Failor K., Werth J., Bayless‐edwards A., Schmale D. (2020). Spatiotemporal patterns of microbial composition and diversity in precipitation. Ecological monographs 90(1): e01394. DOI: 10.1002/ecm.1394 https://hal.inrae.fr/hal-02626506v1 Carotenuto, F., Georgiadis, T., Gioli, B., Leyronas, C., Morris, C. E., Nardino, M., Wohlfahrt, Miglietta, F. (2017). Measurements and modeling of surface–atmosphere exchange of microorganisms in Mediterranean grassland. Atmospheric Chemistry and Physics, 17, 14919-14936. DOI : 10.5194/acp-2017-527 https://hal.inrae.fr/hal-01604418 Failor, K. C., Schmale, D. G., Vinatzer, B. A., Monteil, C. L.  (2017). Ice nucleation active bacteria in precipitation are genetically diverse and nucleate ice by employing different mechanisms. ISME Journal, 11, 2740-2753. DOI : 10.1038/ismej.2017.124 https://hal.inrae.fr/hal-01604615 Jimenez-Sanchez, C., Hanlon, Aho, K. A., Powers, C., Morris, C. E., Schmale, D. G. (2018). Diversity and ice nucleation activity of microorganisms collected with a small unmanned aircraft system (sUAS) in France and the United States. Frontiers in Microbiology, 9, 1667. DOI : 10.3389/fmicb.2018.01667https://hal.inrae.fr/hal-02627523 Morris, C. E., Soubeyrand, S., Bigg, E. K., Creamean, J. M., Sands, D. C. (2017). Mapping rainfall feedback to reveal the potential sensitivity of precipitation to biological aerosols. Bulletin of the American Meteorological Society, 98, 1109-1118. DOI : 10.1175/BAMS-D-15-00293.1 https://hal.inrae.fr/hal-02627944v1 Stopelli, E., Conen, F., Guilbaud, C., Zopfi, J., Alewell, Morris, C. E. (2017). Ice nucleators, bacterial cells and Pseudomonas syringae in precipitation at Jungfraujoch. Biogeosciences, 14, 1189-1196. DOI : 10.5194/bg-14-1189-201. https://hal.inrae.fr/hal-01594979 Van Stan J.T., Morris C.E., Aung K., Kuzyakov Y., Magyar D., Rebollar E.A., Remus-Emsermann M., Uroz S., Vandenkoornhuyse P. (2020). Precipitation partitioning - Hydrologic highways between microbial communities of the plant microbiome? In : Van Stan J.T., Gutmann E., Friesen J., Precipitation partitioning by vegetation, p. 229-252, Springer Nature Switzerland, Cham, CHE. DOI: 10.1007/978-3-030-29702-2_14  https://hal.inrae.fr/hal-02389738v1