Abstract

Plant leaves constitute a huge microbial habitat of global importance. How microorganisms survive the dry daytime on leaves and avoid desiccation is not well understood. There is evidence that microscopic surface wetness in the form of thin films and micrometer-sized droplets, invisible to the naked eye, persists on leaves during daytime due to deliquescence - the absorption of water until dissolution - of hygroscopic aerosols. Here we study how such microscopic wetness affects cell survival. We show that, on surfaces drying under moderate humidity, stable microdroplets form around bacterial aggregates due to capillary pinning and deliquescence. Notably, droplet-size increases with aggregate-size, and cell survival is higher the larger the droplet. This phenomenon was observed for 13 bacterial species, two of which - Pseudomonas fluorescens and P. putida - were studied in depth. Microdroplet formation around aggregates is likely key to bacterial survival in a variety of unsaturated microbial habitats, including leaf surfaces.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 2,3 and 5.

Article and author information

Author details

  1. Maor Grinberg

    Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
  2. Tomer Orevi

    Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
  3. Shifra Steinberg

    Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Rehovot, Israel
    Competing interests
    The authors declare that no competing interests exist.
  4. Nadav Kashtan

    Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Rehovot, Israel
    For correspondence
    nadav.kashtan@mail.huji.ac.il
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7475-1363

Funding

James S. McDonnell Foundation (#220020475)

  • Nadav Kashtan

Israel Science Foundation (1396/19)

  • Nadav Kashtan

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Wenying Shou, Fred Hutchinson Cancer Research Center, United States

Version history

  1. Received: May 16, 2019
  2. Accepted: September 20, 2019
  3. Accepted Manuscript published: October 15, 2019 (version 1)
  4. Version of Record published: November 1, 2019 (version 2)

Copyright

© 2019, Grinberg et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Maor Grinberg
  2. Tomer Orevi
  3. Shifra Steinberg
  4. Nadav Kashtan
(2019)
Bacterial survival in microscopic surface wetness
eLife 8:e48508.
https://doi.org/10.7554/eLife.48508

Share this article

https://doi.org/10.7554/eLife.48508

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